JPH09133721A - Correlation function measuring method and device - Google Patents
Correlation function measuring method and deviceInfo
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- JPH09133721A JPH09133721A JP28985195A JP28985195A JPH09133721A JP H09133721 A JPH09133721 A JP H09133721A JP 28985195 A JP28985195 A JP 28985195A JP 28985195 A JP28985195 A JP 28985195A JP H09133721 A JPH09133721 A JP H09133721A
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、信号や各種物理量
の遅延測定や位相測定などを行うための受動型の相関関
数測定方法及び装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a passive type correlation function measuring method and apparatus for performing delay measurement and phase measurement of signals and various physical quantities.
【０００２】[0002]
【従来の技術】被測定伝送路における周波数ごとの遅延
時間や移相量を測定する方法には、大別すると、能動型
の方法と受動型の方法とがある。能動型の方法は、ネッ
トワークアナライザなどで使用されており、試験用信号
を自ら発生して被測定伝送路に入力し、被測定伝送路か
らの出力信号によって被測定伝送路の伝達関数を求める
方法である。この方法では、式(1)に示すように伝達関
数の位相Ｐｈａｓｅ(ｆ)を観測周波数ｆで微分すること
によって、周波数ｆにおける被測定伝送路の遅延時間τ
(ｆ)を容易に求めることができる。2. Description of the Related Art The methods for measuring the delay time and the amount of phase shift for each frequency in a transmission line to be measured are roughly classified into an active method and a passive method. The active method is used in network analyzers, etc., where a test signal is generated by itself and input to the measured transmission line, and the transfer function of the measured transmission line is obtained from the output signal from the measured transmission line. Is. In this method, the phase Phase (f) of the transfer function is differentiated by the observation frequency f as shown in the equation (1), so that the delay time τ of the measured transmission line at the frequency f is
(f) can be easily obtained.
【０００３】[0003]
【数１】 一方、受動型の測定では、外部の信号源で発生した信号
を被測定伝送路に入力させる。この場合、観測できるス
ペクトルが連続であるとは限らず、また、外部の信号源
での変動等によってＳＮ比も一定しないので、遅延量τ
の関数として相互相関関数Ｃ(τ)を式(2)のように定義
し、Ｃ(τ)を最大にする遅延量τmを遅延時間としてい
た。(Equation 1) On the other hand, in the passive type measurement, a signal generated by an external signal source is input to the measured transmission line. In this case, the observable spectrum is not always continuous, and the SN ratio is not constant due to fluctuations in the external signal source.
The cross-correlation function C (τ) is defined as a function of Eq. (2), and the delay amount τ m that maximizes C (τ) is the delay time.
【０００４】[0004]
【数２】 ここでａ(ｔ)及びｂ(ｔ)は、時刻ｔの関数として表わさ
れる観測信号であり、Ｔは相関決定のための測定時間を
表わすパラメータである。図６は、制限された周波数帯
域でこの演算を効率良く実施するための構成を示してい
る。(Equation 2) Where a (t) and b (t) are observed signals represented as a function of time t, and T is a parameter representing the measurement time for determining the correlation. FIG. 6 shows a configuration for efficiently performing this calculation in a limited frequency band.
【０００５】信号源９１からの信号が、それぞれ遅延時
間がτa,τbで表わされる遅延要素９２,９３に入力する
ものとする。各遅延要素９２,９３からの出力が、観測
信号ａ(ｔ),ｂ(ｔ)で表わされている。これら観測信号
ａ(ｔ),ｂ(ｔ)に対してＦＦＴ（高速フーリエ変換）処
理９４,９５を施すことにより、周波数ｆの関数として
のスペクトルＳa(ｆ),Ｓb(ｆ)を算出する。そして、観
測周波数をｆ0、観測周波数帯域の幅をΔｆとして、処
理９６により、式(3)に示される相関関数Ｃab(ｆ0)を算
出し、相関関数Ｃab(ｆ0)の位相を２πｆ0によって除算
し、Δτ(ｆ0)の近似値を求める。なお、*は、複素共役
を示している。It is assumed that the signals from the signal source 91 are input to the delay elements 92 and 93 whose delay times are represented by τ a and τ b , respectively. The output from each delay element 92, 93 is represented by an observed signal a (t), b (t). By performing FFT (Fast Fourier Transform) processing 94 and 95 on these observed signals a (t) and b (t), spectra S a (f) and S b (f) as a function of frequency f are calculated. To do. Then, the observation frequency f 0, the width of the observation frequency band as Delta] f, by the processing 96 calculates a correlation function C ab represented by the formula (3) (f 0), the phase of the correlation function C ab (f 0) Is divided by 2πf 0 to obtain an approximate value of Δτ (f 0 ). Note that * indicates a complex conjugate.
【０００６】[0006]
【数３】 Δτ(ｆ0)は、観測周波数ｆ0における２つの遅延要素９
２,９３の遅延時間τa(ｆ0),τb(ｆ0)の差である。した
がって、被測定伝送路への入力信号を検出してａ(ｔ)と
し、被測定伝送路からの出力信号をｂ(ｔ)とすることに
よって、この被測定伝送路における遅延時間がΔτ
(ｆ0)として求められることになる。(Equation 3) Δτ (f 0 ) is equal to the two delay elements 9 at the observation frequency f 0 .
It is the difference between the delay times τ a (f 0 ), τ b (f 0 ) of 2,93. Therefore, by detecting the input signal to the measured transmission line and setting it as a (t) and setting the output signal from the measured transmission line as b (t), the delay time in this measured transmission line is Δτ.
It will be obtained as (f 0 ).
【０００７】[0007]
【発明が解決しようとする課題】しかしながら、上述し
た受動型の測定は、観測信号ａ(ｔ),ｂ(ｔ)の周波数ス
ペクトルを求める必要があるので高速かつ高精度のアナ
ログ／デジタル変換器を必要とするとともに、ＦＦＴ演
算や上述の式(3)の数値積分など数多くの数値演算を行
わなければならないためにリアルタイムでの解析が難し
い、という問題点を有する。However, in the above passive type measurement, since it is necessary to obtain the frequency spectrum of the observation signals a (t) and b (t), a high-speed and highly accurate analog / digital converter is used. In addition to the necessity, there is a problem that real-time analysis is difficult because a lot of numerical operations such as FFT operation and numerical integration of the above equation (3) have to be performed.
【０００８】本発明の目的は、高速のアナログデジタル
変換器を必要とせず、特に、遅延時間Δτが観測用周波
数帯域Δｆに対して小さい場合（Δτ＜１／Δｆ）に、
高速かつ高精度で相関関数を決定でき、遅延時間Δτを
決定できる相関関数測定方法及び装置を提供することに
ある。The object of the present invention does not require a high-speed analog-digital converter, and particularly when the delay time Δτ is smaller than the observation frequency band Δf (Δτ <1 / Δf),
It is an object of the present invention to provide a correlation function measuring method and apparatus capable of determining a correlation function at high speed and with high accuracy and determining a delay time Δτ.
【０００９】[0009]
【課題を解決するための手段】本発明の相関関数測定方
法は、所定の観測周波数帯域において第１の観測信号と
第２の観測信号の間の相関関数を測定する方法であっ
て、前記第１の観測信号を前記観測周波数帯域に制限し
て第１の周波数の信号に周波数変換し、前記第２の観測
信号を前記観測周波数帯域に制限し、前記第１の周波数
への周波数変換時と同一の基準周波数信号に基づき、前
記第１の周波数に対して所定の周波数差を有する第２の
周波数の信号に前記第２の観測信号を周波数変換し、前
記第１の周波数の信号と前記第２の周波数の信号を乗算
し、これらの差周波数成分に対して前記基準周波数信号
に基準づいてベクトル検波を行う。A correlation function measuring method of the present invention is a method of measuring a correlation function between a first observation signal and a second observation signal in a predetermined observation frequency band, the method comprising: One observation signal is limited to the observation frequency band and frequency-converted to a signal of a first frequency, the second observation signal is limited to the observation frequency band, and the frequency is converted to the first frequency. Based on the same reference frequency signal, the second observation signal is frequency-converted into a signal of a second frequency having a predetermined frequency difference with respect to the first frequency, and the signal of the first frequency and the signal of the first frequency are converted. Signals of two frequencies are multiplied, and vector detection is performed on these difference frequency components based on the reference frequency signal.
【００１０】本発明の方法では、上述の式(3)に基づく
演算を行う代わりに、第１の観測信号及び第２の観測信
号を所定の観測周波数帯域に帯域制限して乗算し、乗算
結果の差周波数成分に対してベクトル検波を施すことに
よって、相関関数に関する情報を得ている。この際、観
測周波数帯域に帯域制限された２信号をそのまま乗算す
ると差周波数成分がほぼ直流成分となること、また、観
測周波数帯域の信号では乗算を行う際に高すぎることな
どから、周波数変換を行い、帯域制限後の第１の観測信
号と第２の観測信号との間に所定の周波数差が生じるよ
うにしている。また、乗算器に入力すべき周波数の信号
に直接変換するのではなく、いったん、第１の観測信号
と第２の観測信号とを同一の中間周波数に変換し、さら
に再度の周波数変換を行ってから乗算器に信号を与える
ようにしてもよい。なお、相関関数の測定では位相情報
を保存しなければならないから、周波数変換やベクトル
検波が同一の基準周波数信号に基づいて行われるよう
に、具体的には例えば局部発振器をこの基準周波数信号
に位相ロックさせるようにする必要がある。In the method of the present invention, instead of performing the calculation based on the above equation (3), the first observation signal and the second observation signal are band-limited to a predetermined observation frequency band and multiplied, and the multiplication result Information on the correlation function is obtained by performing vector detection on the difference frequency component of. At this time, if the observed frequency band is multiplied by the band-limited two signals as they are, the difference frequency component becomes almost a direct current component, and the signal in the observed frequency band is too high when performing multiplication. Then, a predetermined frequency difference is generated between the first observed signal and the second observed signal after band limitation. In addition, instead of directly converting into a signal of a frequency to be input to the multiplier, the first observation signal and the second observation signal are first converted into the same intermediate frequency, and then frequency conversion is performed again. It is also possible to give a signal to the multiplier. Since the phase information must be stored in the measurement of the correlation function, so that the frequency conversion and the vector detection are performed based on the same reference frequency signal, specifically, for example, a local oscillator is phased to this reference frequency signal. It needs to be locked.
【００１１】本発明では、ベクトル検波の方法として、
基準周波数信号に基づいて上述の差周波数に相当する参
照信号を発生させてベクトル検波を行なう、合成フーリ
エ積分（ＳＦＩ;Synthesized Fourier Integration）に
基づく方法を好ましく用いることができる。また、受動
型の遅延時間測定を行う場合には、被測定伝送路の出力
信号と入力信号をそれぞれ第１の観測信号と第２の観測
信号とし、ベクトル検波によって得られた位相情報Ｐ
(ｆ0)を観測角周波数２πｆ0で除算すればよい。In the present invention, as a vector detection method,
A method based on Synthesized Fourier Integration (SFI), in which a reference signal corresponding to the above-mentioned difference frequency is generated based on a reference frequency signal and vector detection is performed, can be preferably used. Further, in the case of performing passive type delay time measurement, the output signal and the input signal of the transmission path to be measured are the first observation signal and the second observation signal, respectively, and the phase information P obtained by the vector detection is used.
(f 0 ) may be divided by the observed angular frequency 2πf 0 .
【００１２】本発明の相関関数測定装置は、所定の観測
周波数帯域において第１の観測信号と第２の観測信号の
間の相関関数を測定する装置であって、前記第１の観測
信号を前記観測周波数帯域に制限して所定の中間周波数
の信号に周波数変換する第１の変換手段と、前記第２の
観測信号を前記観測周波数帯域に制限し、前記第１の変
換手段におけるものと同一の基準周波数信号に基づき、
前記第２の観測信号を前記中間周波数の信号に周波数変
換する第２の変換手段と、前記第１の変換手段から供給
される信号と前記第２の変換手段から供給される信号と
を乗算する乗算器と、前記第１の変換手段及び前記第２
の変換手段の少なくとも一方の出力と前記乗算器との設
けられたミキサと、前記ミキサごとに設けられ、前記乗
算器に入力する２信号間に所定の周波数差が生じるよう
に、前記基準周波数信号に位相ロックした局部発振信号
を前記ミキサに供給する局部発振器と、前記乗算器の出
力のうち差周波数成分に対して前記基準周波数信号を基
づいてベクトル検波を行うベクトル検波器と、を有す
る。A correlation function measuring device of the present invention is a device for measuring a correlation function between a first observation signal and a second observation signal in a predetermined observation frequency band, wherein the first observation signal is A first conversion unit that limits the frequency of the signal to a predetermined intermediate frequency by limiting the observation frequency band, and a second conversion unit that limits the second observation signal to the observation frequency band and is the same as that in the first conversion unit. Based on the reference frequency signal,
Second conversion means for frequency-converting the second observation signal into a signal of the intermediate frequency, and a signal supplied from the first conversion means and a signal supplied from the second conversion means are multiplied. A multiplier, the first conversion means and the second
The mixer provided with the output of at least one of the conversion means and the multiplier, and the reference frequency signal so that a predetermined frequency difference is generated between the two signals that are provided for each mixer and input to the multiplier. A local oscillator that supplies a phase-locked local oscillation signal to the mixer, and a vector detector that performs vector detection on the difference frequency component of the output of the multiplier based on the reference frequency signal.
【００１３】[0013]
【発明の実施の形態】次に、本発明の実施の形態につい
て、図面を参照して説明する。図１は本発明の実施の一
形態の相関関数測定装置の構成を示すブロック図であ
り、この装置は、本発明の方法に基づいて、２つの観測
信号ａ(ｔ),ｂ(ｔ)の間の相関、典型的には、観測中心
周波数をｆ0、帯域幅をＢＷとする観測周波数帯域にお
ける両者間の遅延時間Δτ(ｆ0)を測定するためのもの
である。なお、図において周波数値がかっこ書きされて
いるが、これらの周波数値は一例であって、本発明はこ
のような周波数での運用に限定されるものではない。Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a correlation function measuring apparatus according to an embodiment of the present invention. This apparatus is based on the method of the present invention and is used to measure two observation signals a (t) and b (t). It is for measuring the correlation between them, typically, the delay time Δτ (f 0 ) between them in the observation frequency band with the observation center frequency f 0 and the bandwidth BW. It should be noted that although the frequency values are written in parentheses in the figure, these frequency values are examples, and the present invention is not limited to operation at such frequencies.
【００１４】観測信号ａ(ｔ),ｂ(ｔ)を中心周波数ｆ0、
帯域幅ＢＷに帯域制限し、さらに中間周波数ＩＦ（ここ
では２１.４ＭＨｚ）の信号に周波数変換する変換部１
１,１２が設けられている。このうち、変換部１２には
基準周波数信号ｆref（ここでは１０ＭＨｚ）を発振し
て出力する基準発振部（不図示）が内蔵されており、変
換部１１,１２において周波数変換を行うための局部発
振部（不図示）は、この基準周波数信号ｆrefに位相ロ
ックして作動するように構成されている。また、観測中
心周波数ｆ0の範囲は例えば０Ｈｚ〜２６.５ＧＨｚであ
り、帯域幅ＢＷは、例えば、１０Ｈｚ〜３ＭＨｚであ
る。変換部１１,１２は、例えば、ＲＦスペクトルアナ
ライザをゼロスパンモードで動作させることによって実
現する。The observed signals a (t) and b (t) are converted to center frequencies f 0 ,
A conversion unit 1 that limits the band to the bandwidth BW and further performs frequency conversion into a signal of an intermediate frequency IF (here, 21.4 MHz).
1, 12 are provided. Of these, the conversion unit 12 has a built-in reference oscillation unit (not shown) that oscillates and outputs a reference frequency signal f ref (here, 10 MHz), and the conversion units 11 and 12 are used to perform frequency conversion. The oscillating unit (not shown) is configured to operate by being phase locked to the reference frequency signal f ref . Moreover, the range of the observation center frequency f 0 is, for example, 0 Hz to 26.5 GHz, and the bandwidth BW is, for example, 10 Hz to 3 MHz. The conversion units 11 and 12 are realized by operating the RF spectrum analyzer in the zero span mode, for example.
【００１５】各変換部１１,１２の出力側には、それぞ
れ、ミキサ１３,１４が設けられており、ミキサ１３,１
４には、基準周波数信号ｆrefに位相ロックした局部発
振器１５,１６が接続している。ここでは、局部発振器
１５の発振周波数を７ＭＨｚ、局部発振器１６の発振周
波数を６ＭＨｚとして両者の差ｆdを１ＭＨｚとし、ミ
キサ１３によって観測信号ａ(ｔ)が１４.４±１.５ＭＨ
ｚに、ミキサ１４によって観測信号ｂ(ｔ)が１５.４±
１.５ＭＨｚに変換されるようにしている。ミキサ１４
の出力側には、１５.４±１.５ＭＨｚのバンドパスフィ
ルタ１７が設けられ、イメージ周波数が除去されるよう
になっている。Mixers 13 and 14 are provided on the output sides of the converters 11 and 12, respectively.
Connected to 4 are local oscillators 15 and 16 which are phase locked to the reference frequency signal f ref . Here, the oscillation frequency of the local oscillator 15 is 7 MHz, the oscillation frequency of the local oscillator 16 is 6 MHz, the difference f d between them is 1 MHz, and the observed signal a (t) is 14.4 ± 1.5 MH by the mixer 13.
In z, the observed signal b (t) by the mixer 14 is 15.4 ±.
It is designed to be converted to 1.5MHz. Mixer 14
A band-pass filter 17 having a frequency of 15.4 ± 1.5 MHz is provided on the output side to remove the image frequency.
【００１６】バンドパスフィルタ１７の出力とミキサ１
３の出力とが乗算器１８に入力し、１４.４±１.５ＭＨ
ｚに変換された観測信号ａ(ｔ)と１５.４±１.５ＭＨｚ
に変換された観測信号ｂ(ｔ)とが乗算され、乗算結果が
ＳＦＩベクトル検波器１９に入力する。ＳＦＩベクトル
検波器１９は、基準周波数信号ｆreqを基準信号とし
て、乗算結果のうちの差周波数ｆd成分をベクトル検波
し、振幅情報と位相情報Ｐ(ｆ0)を出力する。観測信号
ａ(ｔ),ｂ(ｔ)間の遅延時間Δτ(ｆ0)は、Output of bandpass filter 17 and mixer 1
The output of 3 is input to the multiplier 18, and 14.4 ± 1.5 MH
Observation signal a (t) converted to z and 15.4 ± 1.5 MHz
Is multiplied by the observed signal b (t) that has been converted into, and the multiplication result is input to the SFI vector detector 19. The SFI vector detector 19 vector-detects the difference frequency f d component of the multiplication result using the reference frequency signal f req as a reference signal, and outputs amplitude information and phase information P (f 0 ). The delay time Δτ (f 0 ) between the observed signals a (t) and b (t) is
【００１７】[0017]
【数４】 によって与えられる。なお、上述の装置においては、観
測信号ａ(ｔ)の経路にはバンドパスフィルタが設けられ
ていないが、これは、ＳＦＩベクトル検波器１９におい
て、観測信号ａ(ｔ)のイメージ周波数（２８.４ＭＨ
ｚ）と観測信号ｂ(ｔ)との乗算結果である４３.８ＭＨ
ｚ及び１３ＭＨｚの信号が除去されるからである。(Equation 4) Given by In the above-mentioned device, no bandpass filter is provided in the path of the observation signal a (t), but this is because the SFI vector detector 19 uses the image frequency of the observation signal a (t) (28. 4 MH
z) and the observation signal b (t), which is the multiplication result of 43.8 MH
This is because the z and 13 MHz signals are removed.
【００１８】次に、ＳＦＩベクトル検波器１９の構成に
ついて、図２を用いて説明する。ＳＦＩベクトル検波器
１９は、合成フーリエ積分によって、入力信号のベクト
ル検波を行うものである。Next, the configuration of the SFI vector detector 19 will be described with reference to FIG. The SFI vector detector 19 performs vector detection of the input signal by synthetic Fourier integration.
【００１９】基準周波数信号ｆrefの入力するデジタル
シンセサイザ３１が設けられており、デジタルシンセサ
イザでは、図示するように、基準周波数信号ｆrefに応
じて、階段状に数値が時間変化するデジタル信号が生成
する。このデジタル信号は、一方の正弦波メモリ３４に
入力するとともに、デジタル加算器３３を経て他方の正
弦波メモリ３５に入力する。デジタル加算器３３では、
進相量に相当する位相データが加算される。正弦波メモ
リ３４,３５は、正弦波の１周期を等分した各時間ごと
に正弦波でのそのときの値を格納したものであって、一
定の増分でクロックに同期して値が変化するデジタル信
号を与えることにより、正弦波に相当して値が変化する
デジタル信号を出力する。正弦波メモリ３４,３５の出
力側には、それぞれ、デジタル信号とアナログ信号とを
乗算するアナログデジタル乗算器３６,３７が設けられ
ており、デジタル信号として正弦波メモリ３４,３５の
出力がそれぞれアナログデジタル乗算器３６,３７に入
力している。A digital synthesizer 31 to which the reference frequency signal f ref is input is provided. As shown in the figure, the digital synthesizer 31 generates a digital signal whose numerical value changes stepwise according to the reference frequency signal f ref. To do. This digital signal is input to one of the sine wave memories 34, and is also input to the other sine wave memory 35 via the digital adder 33. In the digital adder 33,
Phase data corresponding to the amount of phase advance is added. The sine wave memories 34 and 35 store the value of the sine wave at each time, which is obtained by equally dividing one cycle of the sine wave, and the value changes at a constant increment in synchronization with the clock. By applying a digital signal, a digital signal whose value changes corresponding to a sine wave is output. On the output sides of the sine wave memories 34 and 35, analog digital multipliers 36 and 37 for multiplying a digital signal and an analog signal, respectively, are provided, and the outputs of the sine wave memories 34 and 35 are analog signals. It is input to the digital multipliers 36 and 37.
【００２０】一方、アナログ信号である入力信号は、バ
ンドパスフィルタ３２を介して、アナログデジタル乗算
器３６,３７のアナログ側の入力端子に供給されてい
る。アナログデジタル乗算器３６,３７の出力は、それ
ぞれ、積分器３８,３９を介し、アナログデジタル変換
器４０,４１に入力する。そして、各アナログデジタル
変換器４０,４１の出力は演算・表示部４２に入力し、
ベクトル検波結果が算出されて位相や振幅情報が出力す
る。On the other hand, the input signal which is an analog signal is supplied to the analog-side input terminals of the analog-digital multipliers 36 and 37 via the bandpass filter 32. The outputs of the analog-digital multipliers 36, 37 are input to the analog-digital converters 40, 41 via the integrators 38, 39, respectively. Then, the outputs of the analog-digital converters 40 and 41 are input to the calculation / display unit 42,
The vector detection result is calculated and the phase and amplitude information is output.
【００２１】結局、このＳＦＩベクトル検波器１９で
は、デジタルシンセサイザ３１と正弦波メモリ３４,３
５を使用することによって、基準周波数信号ｆrefに位
相がロックした任意の周波数の正弦波をこのＳＦＩベク
トル検波器１９での参照信号として発生させることがで
きる。そして、各アナログデジタル乗算器３６,３７で
は、基準周波数信号ｆrefから合成された所定の周波数
（上述の例では１ＭＨｚ）の正弦波信号（参照信号）と
入力信号とが乗算され、乗算結果が積分器３８,３９で
積分される。したがって、デジタル加算器で加える位相
データを移相量π／４に相当する値とすることにより、
入力信号のうちの周波数が１ＭＨｚである成分につい
て、余弦（コサイン）成分と正弦（サイン）成分が抽出
されることとなり、ベクトル検波が実現されたことにな
る。After all, in this SFI vector detector 19, the digital synthesizer 31 and the sine wave memories 34 and 3 are used.
By using 5, a sine wave having an arbitrary frequency whose phase is locked to the reference frequency signal f ref can be generated as a reference signal in the SFI vector detector 19. Then, in each of the analog-digital multipliers 36 and 37, the sine wave signal (reference signal) of the predetermined frequency (1 MHz in the above example) synthesized from the reference frequency signal f ref is multiplied by the input signal, and the multiplication result is It is integrated by integrators 38 and 39. Therefore, by setting the phase data added by the digital adder to a value corresponding to the phase shift amount π / 4,
The cosine (sine) component and the sine (sine) component are extracted from the component of the input signal having a frequency of 1 MHz, which means that the vector detection is realized.
【００２２】以上、本発明の実施の形態の一つを説明し
たが、観測周波数の帯域幅ＢＷがベクトル検波の周波数
（１ＭＨｚ）よりも十分に狭い場合には、観測信号ａ
(ｔ)側のミキサ１３と局部発振器１５を省略することも
可能である。図３はこの場合の相関関数測定装置の構成
を示しており、観測信号ｂ(ｔ)側の局部発振器１６の発
振周波数を１ＭＨｚとし、乗算器１８には２０.４ＭＨ
ｚに周波数変換された観測信号ｂ(ｔ)と、中間周波数Ｉ
Ｆ（２１.４ＭＨｚ）に周波数変換された観測信号ａ
(ｔ)が入力する。Although one of the embodiments of the present invention has been described above, when the bandwidth BW of the observed frequency is sufficiently narrower than the frequency of vector detection (1 MHz), the observed signal a
It is also possible to omit the mixer 13 and the local oscillator 15 on the (t) side. FIG. 3 shows the configuration of the correlation function measuring apparatus in this case, in which the oscillation frequency of the local oscillator 16 on the observed signal b (t) side is 1 MHz, and the multiplier 18 is 20.4 MHz.
Observation signal b (t) frequency-converted to z and intermediate frequency I
Observation signal a converted to F (21.4 MHz)
(t) enters.
【００２３】次に、上述の相関関数測定装置を用いた測
定例について説明する。図４に示した例では、信号波源
６１に対して回路網Ａ６２、回路網Ｂ６３、…が直列に
接続されている。回路網Ａ６２の入力信号（信号波源６
１の出力信号）を観測信号ａ(ｔ)とし回路網Ａ６２の出
力信号を観測信号ｂ(ｔ)として引き出すことにより、回
路網Ａ６２の動作状態や遅延特性が測定されている。こ
の場合、信号波源６１から回路網Ａ６２に入力する信号
や回路網Ａ６２の出力信号は電気的な信号である必要は
なく、各種センサを通じて計測される、例えば、温度、
流量、音圧、変位量などの物理量で表わされるものであ
ってもよく、観測信号ａ(ｔ)とｂ(ｔ)が別の物理量で表
わされていてもよい。これらの場合でも、例えば遅延時
間Δτ(ｆ0)から、伝搬速度や、単位時間当りの流量、
伝搬距離等を求めることができる。このように、回路網
や伝送路の任意の点から観測信号を引き出すことによ
り、動作状態の測定を行うことができる。Next, a measurement example using the above correlation function measuring device will be described. In the example shown in FIG. 4, the circuit network A 62, the circuit network B 63, ... Are connected in series to the signal wave source 61. Input signal of the network A62 (signal wave source 6
The output state of the circuit network A62 is measured by observing the output signal of the circuit network A62 as the observed signal a (t) and the output signal of the circuit network A62 as the observed signal b (t). In this case, the signal input from the signal wave source 61 to the circuit network A62 or the output signal of the circuit network A62 does not need to be an electrical signal, and is measured through various sensors, for example, temperature,
It may be represented by a physical quantity such as a flow rate, sound pressure, or a displacement amount, and the observation signals a (t) and b (t) may be represented by different physical quantities. Even in these cases, for example, from the delay time Δτ (f 0 ) to the propagation velocity, the flow rate per unit time,
The propagation distance and the like can be obtained. In this way, the operation state can be measured by extracting the observation signal from an arbitrary point of the circuit network or the transmission line.
【００２４】図５に示した例は、本発明による相関関数
測定装置を複素相関器として波動干渉器に使用し、ホロ
グラムの記録を行うものである。音波や電波も波動であ
ることでは光とは変わらないから、レーザ光を用いる場
合と同じ原理によって、ホログラム像を得ることができ
る（例えば、上羽 貞行、"音波ホログラフィと騒音源
探査"、計測と制御、第１６巻第５号、４２７〜４３３
頁、１９７７年）。ただしこの場合には波長が光の場合
に比べて格段に長いから、固定センサ７２と走査センサ
７３とを用意し、ホログラム観測面７１内で走査センサ
７３をｘｙ方向に２次元的に走査させながらデータを取
得し、計算処理によってホログラム像を再生する。すな
わち、固定センサ７２からの信号を観測信号ａ(ｔ)と
し、走査センサ７３からの信号を観測信号ｂ(ｔ)とし
て、本実施の形態の相関関数測定装置１を用いて、ホロ
グラム観測面７１上の各点(ｘ,ｙ)についてのＳＦＩベ
クトル検波情報（振幅と位相）Ｃab(ｘ,ｙ)を測定す
る。そして、測定された振幅情報と位相情報に基づき、
ホログラム像再生装置７４によってホログラム像を再生
し、これを像表示装置７５で表示すればよい。ホログラ
ム像から波源の広がりなどを知ることができる。In the example shown in FIG. 5, a hologram is recorded by using the correlation function measuring apparatus according to the present invention as a complex correlator in a wave interferometer. Since sound waves and radio waves are similar to light when they are waves, hologram images can be obtained by the same principle as when using laser light (for example, Sadayuki Ueba, "Sound holography and noise source exploration", measurement And control, Vol. 16, No. 5, 427-433
P., 1977). However, in this case, since the wavelength is much longer than that of light, the fixed sensor 72 and the scanning sensor 73 are prepared, and the scanning sensor 73 is two-dimensionally scanned in the xy directions within the hologram observation surface 71. Data is acquired and a hologram image is reproduced by calculation processing. That is, the signal from the fixed sensor 72 is used as the observation signal a (t), and the signal from the scanning sensor 73 is used as the observation signal b (t). The SFI vector detection information (amplitude and phase) C ab (x, y) for each point (x, y) above is measured. Then, based on the measured amplitude information and phase information,
The hologram image may be reproduced by the hologram image reproducing device 74 and displayed on the image display device 75. You can know the spread of the wave source from the hologram image.
【００２５】なお、観測中心周波数ｆ0と観測周波数帯
域幅ＢＷを可変として波源再生像（ホログラム像）の比
較を行うことによって、波源とホログラム観測面との間
の距離や波源の性質などを詳しく知ることができる。ホ
ログラム観測面から波源までの距離は、再生された波源
像の位相を観測中心周波数ｆ0で微分することによって
得られる。観測中心周波数ｆ0と帯域幅ＢＷを変化させ
た再生像を比較し振幅分布と位相分布の差異を利用する
ことにより、波源間の相関関係を知ることができる。It should be noted that the observation center frequency f 0 and the observation frequency bandwidth BW are made variable to compare the reproduction image (hologram image) of the wave source, so that the distance between the wave source and the hologram observation surface, the nature of the wave source, etc. can be detailed. I can know. The distance from the hologram observation surface to the wave source is obtained by differentiating the phase of the reproduced wave source image by the observation center frequency f 0 . The correlation between the wave sources can be known by comparing the observed center frequency f 0 and the reproduced image in which the bandwidth BW is changed and utilizing the difference between the amplitude distribution and the phase distribution.
【００２６】[0026]
【発明の効果】以上説明したように本発明は、２つの観
測信号ａ(ｔ),ｂ(ｔ)に対して観測周波数帯域に応じた
帯域制限を行った後に、これらの間に所定の周波数差が
生じるように周波数変換を行ってから乗算し、乗算結果
に対してベクトル検波を行うことにより、高速のアナロ
グデジタル変換器を必要とせず、複雑な数値計算も必要
とせず、リアルタイムで被測定伝送路の遅延時間等を計
算できるようになるという効果がある。As described above, according to the present invention, two observation signals a (t) and b (t) are subjected to band limitation according to the observation frequency band, and then a predetermined frequency is placed between them. By performing frequency conversion so that there is a difference and then multiplying, and performing vector detection on the multiplication result, there is no need for a high-speed analog-to-digital converter, no complicated numerical calculation, and real-time measurement There is an effect that the delay time and the like of the transmission line can be calculated.
【図１】本発明の実施の一形態の相関関数測定装置の構
成を示すブロック図である。FIG. 1 is a block diagram showing a configuration of a correlation function measuring apparatus according to an embodiment of the present invention.
【図２】ＳＦＩベクトル検波器の構成を示すブロック図
である。FIG. 2 is a block diagram illustrating a configuration of an SFI vector detector.
【図３】本発明の別の実施の形態の相関関数測定装置の
構成を示すブロック図である。FIG. 3 is a block diagram showing a configuration of a correlation function measuring device according to another embodiment of the present invention.
【図４】測定例を説明するブロック図である。FIG. 4 is a block diagram illustrating a measurement example.
【図５】測定例を説明するブロック図である。FIG. 5 is a block diagram illustrating a measurement example.
【図６】従来の受動型の遅延時間測定を説明する図であ
る。FIG. 6 is a diagram illustrating a conventional passive type delay time measurement.
１ 相関関数測定装置 １１，１２ 変換部 １３，１４ ミキサ １５，１６ 局部発振器 １７ バンドパスフィルタ １８ 乗算器 １９ ＳＦＩベクトル検波器 ３１ デジタルシンセサイザ ３２ バンドパスフィルタ ３３ デジタル加算器 ３４，３５ 正弦波メモリ ３６，３７ アナログデジタル乗算器 ３８，３９ 積分器 ４０，４１ アナログデジタル変換器 ４２ 演算・表示部 ６１ 信号波源 ６２，６３ 回路網 ７１ ホログラム観測面 ７２ 固定センサ ７３ 走査センサ ７４ ホログラム像再生装置 ７５ 像表示装置 1 Correlation Function Measuring Device 11, 12 Conversion Unit 13, 14 Mixer 15, 16 Local Oscillator 17 Bandpass Filter 18 Multiplier 19 SFI Vector Detector 31 Digital Synthesizer 32 Bandpass Filter 33 Digital Adder 34, 35 Sine Wave Memory 36, 37 analog-digital multiplier 38, 39 integrator 40, 41 analog-digital converter 42 arithmetic / display unit 61 signal wave source 62, 63 circuit network 71 hologram observation surface 72 fixed sensor 73 scanning sensor 74 hologram image reproducing device 75 image display device
Claims (6)
測信号と第２の観測信号の間の相関関数を測定する方法
であって、 前記第１の観測信号を前記観測周波数帯域に制限して第
１の周波数の信号に周波数変換し、 前記第２の観測信号を前記観測周波数帯域に制限し、前
記第１の周波数への周波数変換時と同一の基準周波数信
号に基づき、前記第１の周波数に対して所定の周波数差
を有する第２の周波数の信号に前記第２の観測信号を周
波数変換し、 前記第１の周波数の信号と前記第２の周波数の信号を乗
算し、これらの差周波数成分に対して前記基準周波数信
号に基づいてベクトル検波を行う相関関数測定方法。1. A method of measuring a correlation function between a first observation signal and a second observation signal in a predetermined observation frequency band, wherein the first observation signal is limited to the observation frequency band. The first frequency is converted into a signal of a first frequency, the second observation signal is limited to the observation frequency band, and the first frequency is converted based on the same reference frequency signal as in the frequency conversion to the first frequency. To the second frequency signal having a predetermined frequency difference with respect to the second observation signal by frequency conversion, and the first frequency signal and the second frequency signal are multiplied, A correlation function measuring method for performing vector detection on a component based on the reference frequency signal.
測信号と第２の観測信号の間の相関関数を測定する方法
であって、 前記第１の観測信号を前記観測周波数帯域に制限して所
定の中間周波数の信号に周波数変換し、 前記第２の観測信号を前記観測周波数帯域に制限し、前
記第１の観測信号の場合におけるものと同一の基準周波
数信号に基づき、前記第２の観測信号を前記中間周波数
の信号に周波数変換し、 前記中間周波数への変換後の前記第１の観測信号及び前
記第２の観測信号の少なくとも一方に対して前記基準周
波数信号に基づいて周波数変換を行い、前記第１の観測
信号と前記第２観測信号の間に所定の周波数差を生じさ
せ、 前記周波数差が生じた前記第１の観測信号と前記第２の
観測信号とを乗算し、乗算の結果として生じる差周波数
成分に対して前記基準周波数信号に基づいてベクトル検
波を行う相関関数測定方法。2. A method for measuring a correlation function between a first observation signal and a second observation signal in a predetermined observation frequency band, wherein the first observation signal is limited to the observation frequency band. Frequency conversion to a signal of a predetermined intermediate frequency, limiting the second observation signal to the observation frequency band, based on the same reference frequency signal as in the case of the first observation signal, the second observation The signal is frequency-converted into a signal of the intermediate frequency, and frequency conversion is performed on at least one of the first observation signal and the second observation signal after conversion to the intermediate frequency based on the reference frequency signal. , A predetermined frequency difference is generated between the first observation signal and the second observation signal, and the first observation signal and the second observation signal having the frequency difference are multiplied, Result Correlation function measuring method for performing vector detection based on the reference frequency signal to the frequency components.
により、前記基準周波数信号に基づいて前記周波数差に
相当する参照信号を生成して行われる請求項１または２
に記載の相関関数測定方法。3. The vector detection is performed by generating a reference signal corresponding to the frequency difference based on the reference frequency signal by synthetic Fourier integration.
Correlation function measuring method described in.
情報を観測周波数で除算することにより、前記第１の観
測信号と前記第２の観測信号の間の遅延時間を決定する
請求項１乃至３いずれか１項に記載の相関関数決定方
法。4. The delay time between the first observation signal and the second observation signal is determined by dividing the phase information obtained by the vector detection by the observation frequency. Or the correlation function determination method described in item 1.
測信号と第２の観測信号の間の相関関数を測定する装置
であって、 前記第１の観測信号を前記観測周波数帯域に制限して所
定の中間周波数の信号に周波数変換する第１の変換手段
と、 前記第２の観測信号を前記観測周波数帯域に制限し、前
記第１の変換手段におけるものと同一の基準周波数信号
に基づき、前記第２の観測信号を前記中間周波数の信号
に周波数変換する第２の変換手段と、 前記第１の変換手段から供給される信号と前記第２の変
換手段から供給される信号とを乗算する乗算器と、 前記第１の変換手段及び前記第２の変換手段の少なくと
も一方の出力と前記乗算器との設けられたミキサと、 前記ミキサごとに設けられ、前記乗算器に入力する２信
号間に所定の周波数差が生じるように、前記基準周波数
信号に位相ロックした局部発振信号を前記ミキサに供給
する局部発振器と、 前記乗算器の出力のうち差周波数成分に対して前記基準
周波数信号を基づいてベクトル検波を行うベクトル検波
器と、を有する相関関数測定装置。5. An apparatus for measuring a correlation function between a first observation signal and a second observation signal in a predetermined observation frequency band, wherein the first observation signal is limited to the observation frequency band. A first conversion means for performing frequency conversion into a signal of a predetermined intermediate frequency; and limiting the second observation signal to the observation frequency band, based on the same reference frequency signal as in the first conversion means, Second conversion means for frequency-converting the second observation signal into the intermediate frequency signal, and multiplication for multiplying the signal supplied from the first conversion means by the signal supplied from the second conversion means. And a mixer provided with the output of at least one of the first conversion means and the second conversion means and the multiplier, and between two signals provided for each mixer and input to the multiplier. The predetermined frequency difference As described above, a local oscillator that supplies a local oscillation signal phase-locked to the reference frequency signal to the mixer, and a vector detection based on the reference frequency signal for the difference frequency component of the output of the multiplier is performed. A vector detector, and a correlation function measuring device having a vector detector.
信号から前記周波数差に相当する参照信号を生成してベ
クトル検波を行なう合成フーリエ積分ベクトル検波器で
ある請求項５に記載の相関関数測定装置。6. The correlation function measuring device according to claim 5, wherein the vector detector is a synthetic Fourier integral vector detector that performs a vector detection by generating a reference signal corresponding to the frequency difference from the reference frequency signal. .
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|---|---|---|---|
| JP28985195A JP3609177B2 (en) | 1995-11-08 | 1995-11-08 | Correlation function measurement method and apparatus |
| US08/746,293 US5748314A (en) | 1995-11-08 | 1996-11-07 | Correlation function measurement method and apparatus, and wave source image visualization method and apparatus based on correlation function measurement |
| DE19645953A DE19645953B4 (en) | 1995-11-08 | 1996-11-07 | Method for determining a correlation and apparatus for carrying out the method |
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| JP28985195A JP3609177B2 (en) | 1995-11-08 | 1995-11-08 | Correlation function measurement method and apparatus |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19921947B4 (en) * | 1998-05-13 | 2005-12-22 | Advantest Corp. | Method and apparatus for reconstructing the distribution of radio wave sources |
| DE19917661B4 (en) * | 1998-04-17 | 2007-02-15 | Advantest Corp. | Method and device for measuring electromagnetic waves |
| KR100900593B1 (en) * | 2002-06-18 | 2009-06-02 | 김칠수 | Method for time interval precision measurement using frequency conversion |
| CN105739289A (en) * | 2016-03-18 | 2016-07-06 | 山东交通学院 | Measuring method and circuit for pulse time interval based on integrated phase detection discriminator |
| CN106896709A (en) * | 2015-11-25 | 2017-06-27 | 英特尔Ip公司 | High frequency time interleaved Digital time converter DTC |
| KR20180054337A (en) * | 2016-11-15 | 2018-05-24 | 한국전자통신연구원 | Apparatus for measuring passive intermodulation distortion signal and method for using the same |
-
1995
- 1995-11-08 JP JP28985195A patent/JP3609177B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19917661B4 (en) * | 1998-04-17 | 2007-02-15 | Advantest Corp. | Method and device for measuring electromagnetic waves |
| DE19921947B4 (en) * | 1998-05-13 | 2005-12-22 | Advantest Corp. | Method and apparatus for reconstructing the distribution of radio wave sources |
| KR100900593B1 (en) * | 2002-06-18 | 2009-06-02 | 김칠수 | Method for time interval precision measurement using frequency conversion |
| CN106896709A (en) * | 2015-11-25 | 2017-06-27 | 英特尔Ip公司 | High frequency time interleaved Digital time converter DTC |
| CN105739289A (en) * | 2016-03-18 | 2016-07-06 | 山东交通学院 | Measuring method and circuit for pulse time interval based on integrated phase detection discriminator |
| KR20180054337A (en) * | 2016-11-15 | 2018-05-24 | 한국전자통신연구원 | Apparatus for measuring passive intermodulation distortion signal and method for using the same |
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| Publication number | Publication date |
|---|---|
| JP3609177B2 (en) | 2005-01-12 |
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