JP6548120B2

JP6548120B2 - Frequency calibration system

Info

Publication number: JP6548120B2
Application number: JP2015199829A
Authority: JP
Inventors: 信泰志賀; 哲安田; 耕太木戸
Original assignee: National Institute of Information and Communications Technology
Current assignee: National Institute of Information and Communications Technology
Priority date: 2015-10-08
Filing date: 2015-10-08
Publication date: 2019-07-24
Anticipated expiration: 2035-10-08
Also published as: JP2017073678A

Description

この発明は、高精度のマスタークロックの基準周波数を用いて、比較的低精度であるスレーブクロックの発振周波数を校正する周波数校正システムに関する。 The present invention relates to a frequency calibration system that calibrates a relatively low precision oscillation frequency of a slave clock using a high precision master clock reference frequency.

従来より、無線通信によって時計の同期を行うシステムは種々提案されている。そして、通信周波数の１クロックよりも小さな誤差を補正するために、ＧＰＳ衛星から衛星クロックによる時間情報をマスターサイトとスレーブサイトで同時に受信し、マスターサイトではマスタークロックと衛星クロックとの差分を求め、スレーブサイトではスレーブクロックと衛星クロックとの差分を求め、地上のネットワークを介してマスターサイトから得たクロックの差分情報を使用して、スレーブサイトがクロック補正値を決定する技術が提案されている（例えば、特許文献１を参照）。 Heretofore, various systems for synchronizing clocks by wireless communication have been proposed. Then, in order to correct an error smaller than one clock of the communication frequency, time information by the satellite clock is simultaneously received from the GPS satellite at the master site and the slave site, and a difference between the master clock and the satellite clock is obtained at the master site At the slave site, a technique has been proposed in which the slave site determines the clock correction value by obtaining the difference between the slave clock and the satellite clock, and using the difference information of the clock obtained from the master site via the ground network See, for example, Patent Document 1).

特許文献１に記載の発明では、ＧＰＳ衛星に搭載された衛星クロックの発振周波数を仲介として、マスターサイトが備えるマスタークロックとスレーブサイトが備えるスレーブクロックとの位相差を求めることができ、この位相差に基づいてスレーブクロックの発振周波数を校正すれば、比較的低精度のスレーブクロックをマスタークロックに匹敵する高精度の発振器として利用できる。 In the invention described in Patent Document 1, the phase difference between the master clock provided at the master site and the slave clock provided at the slave site can be determined by using the oscillation frequency of the satellite clock mounted on the GPS satellite as a mediator. If the oscillation frequency of the slave clock is calibrated based on the above, the relatively low precision slave clock can be used as a high precision oscillator comparable to the master clock.

米国特許出願公開第２００３／００８３１０３号明細書US Patent Application Publication No. 2003/0083103

しかしながら、上記特許文献１に記載された発明では、ＧＰＳ衛星からの時間情報をマスターサイトとスレーブサイトで同時に受信する必要があるため、事前の準備が非常に煩雑であり、利便性が高いとは言えないし、その分だけ高コストになってしまう。加えて、特許文献１に記載の発明では、ＧＰＳ衛星から情報を受信した後に，マスターサイトとスレーブサイト間で受信データを比較する必要があるために、別途通信手段を設けなければならない点でも、利便性が低い。 However, in the invention described in Patent Document 1, it is necessary to simultaneously receive time information from GPS satellites at the master site and the slave site, so that preparation in advance is very complicated and convenience is high. It can not be said, it will be expensive for that much. In addition, in the invention described in Patent Document 1, it is also necessary to separately provide communication means because it is necessary to compare received data between the master site and the slave site after receiving information from the GPS satellite. The convenience is low.

そこで、本発明は、マスター局におけるマスタークロックの周波数発生器とスレーブ局におけるスレーブクロックの周波数発生器との位相差を簡便かつ低コストで取得して、スレーブクロックの発振周波数を校正できる周波数校正システムの提供を目的とする。 Therefore, according to the present invention, a frequency calibration system capable of calibrating the oscillation frequency of the slave clock by simply and inexpensively acquiring the phase difference between the master clock frequency generator in the master station and the slave clock frequency generator in the slave station. The purpose is to provide

上記課題を解決するために、請求項１に係る周波数校正システムは、時計の基準となり得る高精度の計時基準周波数の信号を生成する周波数発生器が備わったマスタークロックを用いて無線通信を行うマスター局と、自局の通信用周波数信号を生成する周波数発生器が備わった仮基準クロックを有し、該仮基準クロックで生成した搬送波時計の基準となり得る高精度の計時基準周波数の信号を生成する周波数発生器が備わったマスタークロックを用いて無線通信を行うマスター局と、自局の通信用周波数信号を生成する周波数発生器が備わった仮基準クロックを有し、該仮基準クロックで生成した搬送波に所要の送信情報を乗せた校正信号を送信する仮基準局と、自局時計の基準として用いる計時基準周波数の信号を生成する周波数発生器が備わった被校正クロックを備え、前記仮基準局からの校正信号を受信して、被校正クロックの計時基準周波数をマスタークロックの計時基準周波数に校正する１又は複数のスレーブ局と、から成る周波数校正システムであって、前記マスター局には、仮基準局より第１時刻ｔ１に送信された校正信号を受信して、校正信号の搬送波とマスタークロックで生成した基準周波数信号との位相差であるマスター局位相差ΦＭ_t1を求めるマスター局位相差取得手段と、前記第１時刻ｔ１から校正信号の送受信に必要十分な時間が経過した第２時刻ｔ２に、前記マスター局位相差ΦＭ_t1を送信情報として含む校正信号を送信するよう仮基準局へ指示する仮基準局送信制御手段と、を設け、前記仮基準局には、前記マスター局からの送信指示に基づき、仮基準クロックで生成した仮基準周波数の搬送波に送信情報を乗せた校正信号を送信する校正信号送信手段、を設け、前記スレーブ局には、前記仮基準局より第１時刻ｔ１に送信された校正信号を受信して、校正信号の搬送波と被校正クロックで生成した被校正周波数信号との位相差であるスレーブ局位相差ΦＳ_t1を求めるスレーブ局位相差取得手段と、前記仮基準局より第２時刻ｔ２に送信された校正信号を受信して、仮基準局からの送信情報であるマスター局位相差ΦＭ_t1を取得するマスター局情報取得手段と、前記仮基準クロックによる仮基準周波数信号と被校正クロックによる被校正周波数信号との位相差であるスレーブ局位相差ΦＳ_t1と、同じく仮基準クロックによる仮基準周波数信号とマスタークロックによる基準周波数信号との位相差であるマスター局位相差ΦＭ_t1との差を求めることで、被校正クロックによる被校正周波数信号とマスタークロックによる基準周波数信号との位相差である校正位相差ΔΦ_t1を得る校正位相差取得手段と、前記校正位相差取得手段により取得した校正位相差ΔΦ_t1に基づいて、被校正クロックの計時基準周波数がマスタークロックの計時基準周波数となるように位相ロックさせる周波数校正手段と、を設けたことを特徴とする。 In order to solve the above problems, a frequency calibration system according to claim 1 is a master that performs wireless communication using a master clock provided with a frequency generator that generates a signal of a high accuracy clocking reference frequency that can be a reference of a clock. And a temporary reference clock provided with a frequency generator for generating a frequency signal for communication of the own station, and generating a signal with a high accuracy clocking reference frequency which can be a reference of a carrier clock generated by the temporary reference clock A master station that performs wireless communication using a master clock provided with a frequency generator, and a provisional reference clock provided with a frequency generator that generates a communication frequency signal of the own station, and a carrier wave generated by the provisional reference clock A temporary reference station that transmits a calibration signal carrying necessary transmission information on the signal generator, and a frequency generator that generates a signal of a clocking reference frequency that is used as a reference for the local clock. A frequency calibration system comprising: a clock to be calibrated; and one or more slave stations that receive a calibration signal from the temporary reference station and calibrate the clocking reference frequency of the clock to be calibrated to the clocking reference frequency of the master clock. The master station receives the calibration signal transmitted from the temporary reference station at the first time t1, and the master station position is the phase difference between the carrier wave of the calibration signal and the reference frequency signal generated by the master clock. retardation master station phase difference obtaining means for obtaining a .PHI.M _t1, a second time t2 has elapsed need enough time to send and receive the calibration signal from the first time t1, the calibration includes the master station retardation .PHI.M _t1 as transmission information Temporary reference station transmission control means for instructing the temporary reference station to transmit a signal, the temporary reference station receiving the temporary base station based on the transmission instruction from the master station; Calibration signal transmitting means for transmitting a calibration signal carrying transmission information on a carrier wave of a provisional reference frequency generated by a clock, and the slave station receives the calibration signal transmitted at the first time t1 from the provisional reference station Slave station phase difference acquiring means for obtaining a slave station phase difference SS _t1 which is a phase difference between the carrier of the calibration signal and the frequency signal to be calibrated generated by the clock to be calibrated, and transmitted from the temporary reference station at the second time t2 Master station information acquiring means for acquiring the master station phase difference MM _t1 which is the transmission information from the temporary reference station, receiving the corrected signal, and a provisional reference frequency signal by the provisional reference clock and a frequency to be calibrated by the clock to be calibrated signal and the slave station retardation .PHI.S _t1 is the phase difference, like the phase of the reference frequency signal by the temporary reference frequency signal and the master clock by the temporary reference clock By obtaining the difference between the master station retardation .PHI.M _t1, the calibration phase difference obtaining means for obtaining a calibration phase difference .DELTA..PHI _t1 is a phase difference between the reference frequency signal by the calibration frequency signal and the master clock according to the calibration clock is Providing frequency calibration means for phase locking so that the clocking reference frequency of the clock to be calibrated becomes the clocking reference frequency of the master clock based on the calibration phase difference ΔΦ _t1 acquired by the calibration phase difference acquiring means; It features.

また、請求項２に係る発明は、請求項１に記載の周波数校正システムにおいて、前記マスター局の仮基準局送信制御手段による仮基準局への校正信号送信指示は、所定時間毎に連続して行うようにしたことを特徴とする。 The invention according to claim 2 is that, in the frequency calibration system according to claim 1, the calibration signal transmission instruction to the provisional reference station by the provisional reference station transmission control means of the master station is continuously issued at predetermined time intervals. It is characterized in that.

また、請求項３に係る発明は、請求項１又は請求項２に記載の周波数校正システムにおいて、前記マスター局の仮基準局送信制御手段から仮基準局への校正信号送信指示は、有線による直接通信で行うようにしたことを特徴とする。 The invention according to claim 3 is the frequency calibration system according to claim 1 or 2, wherein the calibration signal transmission instruction from the temporary reference station transmission control means of the master station to the temporary reference station is direct communication by wire. It is characterized by having done.

また、請求項４に係る発明は、請求項１〜請求項３の何れか１項に記載の周波数校正システムにおいて、前記マスター局には、仮基準局より第１時刻ｔ１に送信された校正信号を受信した時刻であるマスター局受信時刻ＴＭ_t1を前記マスタークロックより取得するマスター局受信時刻取得手段を設け、前記仮基準局送信制御手段は、前記マスター局位相差ΦＭ_t1およびマスター局受信時刻ＴＭ_t1を送信情報として仮基準局へ指示し、前記スレーブ局には、仮基準局より第１時刻ｔ１に送信された校正信号を受信した時刻であるスレーブ局受信時刻ＴＳ_t1を前記被校正クロックより取得するスレーブ局受信時刻取得手段と、前記マスター局情報取得手段が仮基準局より第２時刻ｔ２に送信された校正信号より取得したマスター局受信時刻ＴＭ_t1と、スレーブ局受信時刻取得手段により取得したスレーブ局受信時刻ＴＳ_t1との差である校正時刻差ΔＴ_t1を求める校正時刻差取得手段と、前記校正時刻差取得手段によって取得された校正時刻差ΔＴ_t1に基づいて、被校正クロックの時刻カウンタを補正する時刻校正手段と、を設けるようにしたことを特徴とする。 The invention according to claim 4 is the frequency calibration system according to any one of claims 1 to 3, wherein the master station receives the calibration signal transmitted from the temporary reference station at a first time t1. There is provided a master station reception time acquisition means for acquiring from the master clock a master station reception time TM _t1 which is a received time, and the temporary reference station transmission control means comprises the master station phase difference MM _t1 and the master station reception time TM _t1 . A slave station which instructs a temporary reference station as transmission information and acquires a slave station reception time TS _t1 which is a time when receiving a calibration signal transmitted from the temporary reference station at a first time t1 from the clock to be calibrated a receiving time acquiring unit, the master station receiving time acquired from the calibration signal transmitted master station information acquisition means than the second time t2 temporary reference station TM _t1 , A calibration time difference obtaining means for obtaining a calibration time difference [Delta] T _t1, which is the difference between the slave station receiving time TS _t1 acquired by the slave station receiving time acquiring unit, the calibration time difference acquired calibration time difference acquired by the means [Delta] T _t1 And time calibration means for correcting the time counter of the clock to be calibrated.

また、請求項５に係る発明は、請求項４に記載の周波数校正システムにおいて、前記スレーブ局の時刻校正手段は、予め定めた時刻補正実行条件が達成されるまで校正時刻差ΔＴを複数回に亘って取得し、その平均である平均値で被校正クロックの時刻を補正するようにしたことを特徴とする。 The invention according to claim 5 is the frequency calibration system according to claim 4, wherein the time calibration means of the slave station makes the calibration time difference ΔT plural times until the predetermined time correction execution condition is achieved. The present invention is characterized in that the time of the clock to be calibrated is corrected with an average value which is acquired over the entire range.

また、請求項６に係る発明は、請求項４又は請求項５に記載の周波数校正システムにおいて、前記スレーブ局の時刻校正手段は、校正時刻差ΔＴから計時基準周波数の逆数の整数倍となる粗調整時刻差ΔＴｃと、計時基準周波数の逆数に満たない微調整時刻差ΔＴｆとを求め、粗調整時刻差ΔＴｃに基づいて被校正クロックの時刻カウンタを校正し、微調整時刻差ΔＴｆを計時基準周波数信号との位相差に換算した時刻微調整位相差ΔΦｆを求めて、前記周波数校正手段へ供給し、前記スレーブ局の周波数校正手段は、時刻校正手段より供給された時刻微調整位相差ΔΦｆに基づいて、位相ロックポイントを修正するようにしたことを特徴とする。 The invention according to claim 6 is the frequency calibration system according to claim 4 or claim 5, wherein the time calibration means of the slave station is a coarse one which is an integral multiple of the reciprocal of the clocking reference frequency from the calibration time difference ΔT. The adjustment time difference ΔTc and the fine adjustment time difference ΔTf less than the reciprocal of the clocking reference frequency are determined, the time counter of the clock to be calibrated is calibrated based on the coarse adjustment time difference ΔTc, and the fine adjustment time difference ΔTf is measured The time fine adjustment phase difference ΔΦ f converted to the phase difference with the signal is obtained and supplied to the frequency calibration means, and the frequency calibration means of the slave station is based on the time fine adjustment phase difference ΔΦ f supplied from the time calibration means It is characterized in that the phase lock point is corrected.

本発明に係る周波数校正システムによれば、マスター局の制御下におかれる仮基準局から第１時刻ｔ１と第２時刻ｔ２に送信する２回分の校正信号を受信可能なスレーブ局において、被校正クロックで生成される被校正周波数とマスタークロックで生成される基準周波数との位相差である校正位相差ΔΦ_t1を簡便に得ることができ、被校正クロックの被校正周波数をマスタークロックの基準周波数と同等精度に校正することが可能となる。しかも、スレーブ局が校正位相差ΔΦ_t1を求めるために必要なマスター局側の情報を、第２時刻ｔ２に送信される校正信号によってスレーブ局へ送ることができるので、マスター局側の情報をマスター局からスレーブ局へ送るための通信手段を別途設ける必要がない点でも利便性が高い。よって、低コストで利便性の高い周波数校正システムを構築できる。 According to the frequency calibration system of the present invention, in the slave station capable of receiving two calibration signals transmitted from the temporary reference station under control of the master station at the first time t1 and the second time t2, the clock to be calibrated is The calibration phase difference ΔΦ _t1 which is the phase difference between the frequency to be calibrated and the reference frequency generated by the master clock can be easily obtained, and the frequency to be calibrated of the clock to be calibrated is equal to the reference frequency of the master clock It is possible to calibrate to the accuracy. Moreover, since the information on the master station side necessary for the slave station to obtain the calibration phase difference ΔΦ _t1 can be sent to the slave station by the calibration signal transmitted at the second time t2, the information on the master station side can be master Convenience is also high in that there is no need to separately provide communication means for transmitting from the station to the slave station. Therefore, it is possible to construct a low-cost and highly convenient frequency calibration system.

本発明に係る周波数校正システムの実施形態を示す概略構成図である。It is a schematic block diagram which shows embodiment of the frequency calibration system which concerns on this invention. 本実施形態に係る周波数校正システムにて行われる通信処理の一例を時系列に示したシーケンス図である。It is the sequence diagram which showed an example of the communication processing performed with the frequency calibration system which concerns on this embodiment in time series.

次に、添付図面に基づいて、本発明に係る周波数校正システムの実施形態につき説明する。なお、本実施形態における周波数校正システムでは、周波数校正に加えて、時刻校正も可能なものとした。 Next, an embodiment of a frequency calibration system according to the present invention will be described based on the attached drawings. In addition to frequency calibration, time calibration is also possible in the frequency calibration system according to the present embodiment.

図１に示す周波数校正システム１は、マスター局２と、該マスター局２と有線で接続されて送信タイミング等を制御される仮基準局３と、該仮基準局３が所定の通信プロトコルに基づいて送信する校正信号を受信可能な第１スレーブ局４ａ、第２スレーブ局４ｂ、第３スレーブ局４ｃ、第４スレーブ局４ｄから成る。なお、第１〜第４スレーブ局４ａ〜４ｄは、例示に過ぎず、１局のスレーブ局のみで構成することもできるし、数百〜数億のスレーブ局が散在していても構わない。また、各スレーブ局４ａ〜４ｄに必須の構成は同じであるから、以下の説明で特にスレーブ局の区別を要しない場合は、単にスレーブ局４という。また、マスター局２と仮基準局３のペアを複数箇所に分散配置すれば、仮基準局３による送信エリアが狭くても、より広範囲にあるスレーブ局４の周波数校正を実現できる。 The frequency calibration system 1 shown in FIG. 1 transmits a master station 2, a provisional reference station 3 connected to the master station 2 by wire and whose transmission timing and the like are controlled, and the provisional reference station 3 based on a predetermined communication protocol. And a second slave station 4b, a third slave station 4c, and a fourth slave station 4d. The first to fourth slave stations 4a to 4d are merely examples, and may be configured of only one slave station, or hundreds to hundreds of millions of slave stations may be scattered. Further, since the configuration essential to each of the slave stations 4a to 4d is the same, in the following description, the slave stations 4 are simply referred to when the distinction between the slave stations is not particularly required. Further, if the pairs of the master station 2 and the temporary reference station 3 are distributed at a plurality of locations, even if the transmission area of the temporary reference station 3 is narrow, frequency calibration of the slave station 4 in a wider range can be realized.

マスター局２は、上記仮基準局３より送信される校正信号（後に詳述する）をアンテナ２１および受信機２２で受信する。この受信機２２では、時計の基準となり得る高精度のマスタークロック２３から供給される周波数信号を用いる。また、受信機２２によって得られた情報はＰＣ等で構成した演算処理装置２４に供給され、この演算処理装置２４によって仮基準局３を制御する。なお、マスター局２から仮基準局３への制御は、無線通信で行う事も可能であるが、有線接続であれば、信頼性の高い制御を行える利点がある。 The master station 2 receives the calibration signal (to be described in detail later) transmitted from the temporary reference station 3 at the antenna 21 and the receiver 22. The receiver 22 uses a frequency signal supplied from a high precision master clock 23 which can be a reference of the watch. Further, the information obtained by the receiver 22 is supplied to an arithmetic processing unit 24 constituted by a PC or the like, and the temporary reference station 3 is controlled by the arithmetic processing unit 24. Although control from the master station 2 to the temporary reference station 3 can be performed by wireless communication, wired connection has an advantage that highly reliable control can be performed.

仮基準局３は、マスター局２の制御下にあり、マスター局２の演算処理装置２４からの指示に基づくタイミングで所要の情報を含んだ校正信号をアンテナ３１より送信する。なお、仮基準局３の送信機３２は、マスター局２の演算処理装置２４から供給された所要情報を、仮基準クロック３３より供給される周波数信号の搬送波に変調信号として乗せて送信する。 The temporary reference station 3 is under control of the master station 2 and transmits a calibration signal including necessary information from the antenna 31 at a timing based on an instruction from the arithmetic processing unit 24 of the master station 2. The transmitter 32 of the temporary reference station 3 transmits the required information supplied from the arithmetic processing unit 24 of the master station 2 on the carrier wave of the frequency signal supplied from the temporary reference clock 33 as a modulation signal and transmits it.

スレーブ局４は、仮基準局３より送信された校正信号をアンテナ４１及び受信機４２で受信する。この受信機４２では、上記マスタークロック２３に比べて精度が落ちる被校正クロック４３から供給される周波数信号を用いる。また、受信機４２によって得られた情報はＰＣ等で構成した演算処理装置４４に供給され、この演算処理装置４４によって被校正クロック４３の校正を行う。すなわち、スレーブ局４で用いるスレーブクロックが、周波数及び時刻の校正対象となる被校正クロック４３である。 The slave station 4 receives the calibration signal transmitted from the temporary reference station 3 at the antenna 41 and the receiver 42. The receiver 42 uses a frequency signal supplied from the calibration clock 43 whose accuracy is lower than that of the master clock 23. Further, the information obtained by the receiver 42 is supplied to an arithmetic processing unit 44 configured by a PC or the like, and the arithmetic processing unit 44 calibrates the clock 43 to be calibrated. That is, the slave clock used in the slave station 4 is the clock 43 to be calibrated which is the calibration target of frequency and time.

次に、周波数校正システム１を構成する各局の詳細な構成を説明する。 Next, the detailed configuration of each station constituting the frequency calibration system 1 will be described.

まず、周波数校正システム１における動作開始に当たっては、マスター局２における演算処理装置２４の仮基準局送信制御手段２４ｂが、仮基準局３における送信機３２の校正信号送信手段３２ａに指示したタイミング（例えば、第１時刻）で、仮基準クロック３３の周波数発生器３３ａによって生成した周波数信号の搬送波に所要情報を変調信号して乗せた校正信号を送信する。ただし、初回の校正信号送信時には、マスター局２の演算処理装置２４から送信すべき所要情報が指示されていない。 First, at the start of the operation in the frequency calibration system 1, the timing when the temporary reference station transmission control means 24b of the processing unit 24 in the master station 2 instructs the calibration signal transmission means 32a of the transmitter 32 in the temporary reference station 3 (for example, At time 1), a calibration signal is transmitted on which the required information is modulated and carried on the carrier wave of the frequency signal generated by the frequency generator 33a of the temporary reference clock 33. However, at the time of the first calibration signal transmission, the required information to be transmitted is not instructed from the arithmetic processing unit 24 of the master station 2.

なお、この校正信号の送信手法は特に限定されるものではなく、マスター局２およびスレーブ局４で容易に受信できる通信プロトコルを用いれば、本発明の周波数校正システム１を導入し易いので、利便性を高められる。例えば、近距離無線通信規格の一つであるＺｉｇＢｅｅ（登録商標）を採用した市販の無線通信装置を仮基準局３として用い、２．４ＧＨｚ帯で校正信号の送信を行えば、無線免許が必要なく、且つマスター局２による仮基準局３の制御も容易である。 The transmission method of this calibration signal is not particularly limited, and it is easy to introduce the frequency calibration system 1 of the present invention if a communication protocol that can be easily received by the master station 2 and the slave station 4 is used, so that the convenience is improved. Can be enhanced. For example, using a commercially available wireless communication device adopting ZigBee (registered trademark), which is one of the short-distance wireless communication standards, as the temporary reference station 3 and transmitting a calibration signal in the 2.4 GHz band, wireless license is not necessary. Also, the control of the temporary reference station 3 by the master station 2 is easy.

上記のようにして、第１時刻に仮基準局３より送信された校正信号を受信するマスター局２では、受信機２２の復調手段２２ａによって校正信号を復調する。この復調処理には、マスタークロック２３の周波数発生器２３ａで発生させた基準周波数と、時刻カウンタ２３ｂによって計時される時刻情報が用いられ、復調信号が時系列に演算処理装置２４へ入力される。なお、マスタークロック２３の時刻カウンタ２３ｂには、極めて高精度の周波数発生器２３ａから計時基準周波数の信号が供給されており、このクロックをカウントすることで、時刻カウンタ２３ｂの時刻は高精度な時刻となる。なお、時刻カウンタ２３ｂにて更新される時刻を可視表示する時刻表示器を別途設けても良い。 As described above, in the master station 2 which receives the calibration signal transmitted from the temporary reference station 3 at the first time, the demodulation means 22a of the receiver 22 demodulates the calibration signal. In this demodulation processing, the reference frequency generated by the frequency generator 23a of the master clock 23 and the time information clocked by the time counter 23b are used, and the demodulation signal is input to the arithmetic processing unit 24 in time series. The clock counter 23b of the master clock 23 is supplied with a signal with a clocking reference frequency from the frequency generator 23a with extremely high precision. By counting this clock, the time of the time counter 23b is highly accurate. It becomes. A time indicator may be separately provided to visibly display the time updated by the time counter 23b.

上記復調手段２２ａからの復調信号は、演算処理装置２４の搬送波位相および時刻取得手段２４ａに入力され、搬送波位相を取得する。この搬送波位相とは、校正信号の搬送波（仮基準局３における仮基準クロック３３の周波数発生器３３ａで発生させた基準周波数信号）とマスタークロック２３の周波数発生器２３ａで生成した基準周波数信号との位相差（以下、マスター局位相差ΦＭ_t1という）である。なお、この搬送波位相および時刻取得手段２４ａでは、マスター局２における校正信号の受信時刻（以下、マスター局受信時刻ＴＭ_t1という）も取得する。 The demodulated signal from the demodulation means 22a is input to the carrier wave phase of the arithmetic processing unit 24 and the time acquisition means 24a to acquire the carrier wave phase. The carrier wave phase is the position of the carrier wave of the calibration signal (the reference frequency signal generated by the frequency generator 33a of the temporary reference clock 33 in the temporary reference station 3) and the reference frequency signal generated by the frequency generator 23a of the master clock 23. It is a phase difference (hereinafter referred to as master station phase difference MM _t1 ). The carrier wave phase and time acquisition means 24a also acquires the reception time of the calibration signal at the master station 2 (hereinafter referred to as the master station reception time TM _t1 ).

このように、マスター局２の受信機２２とマスタークロック２３と演算処理装置２４が協働することで、「仮基準局より第１時刻に送信された校正信号を受信して、校正信号の搬送波とマスタークロックで生成した基準周波数信号との位相差であるマスター局位相差ΦＭ_t1を求めるマスター局位相差取得手段」としての機能と、「仮基準局より第１時刻に送信された校正信号を受信した時刻であるマスター局受信時刻ＴＭ_t1を前記マスタークロックより取得するマスター局受信時刻取得手段」としての機能を備えるものとなる。なお、マスター局位相差取得手段およびマスター局受信時刻取得手段によるマスター局位相差ΦＭ_t1、マスター局受信時刻ＴＭ_t1の取得手法は特に限定されるものではなく、デジタル無線通信の直交変調・復調の原理を用いたデジタル処理で求めても良いし、アナログ的に求めるようにしても構わない。 In this manner, the receiver 22 of the master station 2, the master clock 23, and the arithmetic processing unit 24 cooperate with each other to “receive the calibration signal transmitted from the temporary reference station at the first time, and A function as a master station phase difference acquisition means for obtaining a master station phase difference MM _t1 which is a phase difference from a reference frequency signal generated by a master clock, and “a calibration signal transmitted at a first time from a temporary reference station is received It has a function as “master station reception time acquisition means” for acquiring from the master clock the master station reception time TM _t1 that is the time. The method of acquiring the master station phase difference MM _t1 and the master station reception time TM _t1 by the master station phase difference acquisition means and the master station reception time acquisition means is not particularly limited, and quadrature modulation / demodulation of digital wireless communication It may be determined by digital processing using the principle, or may be determined in an analog manner.

上記のようにして搬送波位相および時刻取得手段２４ａにより取得されたマスター局位相差ΦＭ_t1、マスター局受信時刻ＴＭ_t1は、演算処理手段２４の仮基準局送信制御手段２４ｂへ供給され、上記第１時刻から校正信号の送受信に必要十分な時間（例えば、０．１秒）が経過した第２時刻に、前記マスター局位相差ΦＭ_t1およびマスター局受信時刻ＴＭ_t1を送信情報として含む校正信号を送信するよう仮基準局３における送信機３２の校正信号送信手段３２ａへ指示する。なお、周波数校正システム１としては、校正信号に含ませる送信情報はマスター局位相差ΦＭ_t1だけでも良いが、マスター局受信時刻ＴＭ_t1も併せて送信情報に含ませるようにすれば、スレーブ局４の時刻を高精度に校正することが可能となる。 The master station phase difference MM _t1 and the master station reception time TM _t1 acquired by the carrier wave phase and time acquisition means 24a as described above are supplied to the temporary reference station transmission control means 24b of the arithmetic processing means 24, and the first time Transmits the calibration signal including the master station phase difference MM _t1 and the master station reception time TM _t1 as transmission information at a second time when a time (for example, 0.1 second) necessary and sufficient for transmission and reception of the calibration signal has passed from It instructs the calibration signal transmitting means 32 a of the transmitter 32 in the temporary reference station 3. As the frequency calibration system 1, although the transmission information included in the calibration signal may be only the master station phase difference MM _t1, if the master station reception time TM _t1 is also included in the transmission information, the slave station 4 It is possible to calibrate the time of day with high accuracy.

そして、マスター局２における演算処理装置２４の仮基準局送信制御手段２４ｂからの送信指示を受けた仮基準局３における送信機３２の校正信号送信手段３２ａは、第２時刻に、仮基準クロック３３の周波数発生器３３ａで生成した仮基準周波数の搬送波に送信情報（マスター局位相差ΦＭ_t1およびマスター局受信時刻ＴＭ_t1）を変調して搬送波に乗せた校正信号（２回目）を送信する。 The calibration signal transmission unit 32a of the transmitter 32 in the temporary reference station 3 receiving the transmission instruction from the temporary reference station transmission control unit 24b of the arithmetic processing unit 24 in the master station 2 calculates the frequency of the temporary reference clock 33 at the second time. The transmission information (master station phase difference MM _t1 and master station reception time TM _t1 ) is modulated on the carrier wave of the provisional reference frequency generated by the generator 33a, and the calibration signal (second time) placed on the carrier wave is transmitted.

上記のようにして第２時刻に仮基準局３より送信された校正信号（２回目）を受信したマスター局２では、上述したと同様に、マスター局位相差ΦＭ_t2およびマスター局受信時刻ＴＭ_t2を取得し、上記第２時刻から校正信号の送受信に必要十分な時間（例えば、０．１秒）が経過した第３時刻に、前記マスター局位相差ΦＭ_t2およびマスター局受信時刻ＴＭ_t2を送信情報として含む校正信号を送信するよう仮基準局３における送信機３２の校正信号送信手段３２ａへ指示する。これにより、仮基準局３における送信機３２の校正信号送信手段３２ａは、第３時刻に、仮基準クロック３３の周波数発生器３３ａで生成した仮基準周波数の搬送波に送信情報（マスター局位相差ΦＭ_t2およびマスター局受信時刻ＴＭ_t2）を乗せた校正信号（３回目）を送信する。 As described above, in the master station 2 that receives the calibration signal (second time) transmitted from the temporary reference station 3 at the second time as described above, the master station phase difference MM _t2 and the master station reception time TM _t2 are The master station phase difference MM _t2 and the master station reception time TM _t2 are transmitted at the third time when acquired and sufficient time (for example, 0.1 second) necessary for transmission and reception of the calibration signal has elapsed from the second time. The calibration signal transmitting means 32a of the transmitter 32 in the temporary reference station 3 is instructed to transmit the calibration signal included as. Thereby, the calibration signal transmitting means 32a of the transmitter 32 in the temporary reference station 3 transmits the carrier information of the temporary reference frequency generated by the frequency generator 33a of the temporary reference clock 33 at the third time (master station phase difference MM _t2 And transmit a calibration signal (third time) carrying the master station reception time TM _t2 ).

以下、同様にして、Ｎ回目の校正信号には、Ｎ−１回目の校正信号受信時にマスター局２が取得した送信情報（マスター局位相差ΦＭ_N-1およびマスター局受信時刻ＴＭ_N-1）が変調されて搬送波に乗せられることとなる。後述するように、スレーブ局４において周波数校正および時刻校正を行うためには、最低限、連続した２回の校正信号を受信できれば良いのであるが、本実施形態の周波数校正システム１のように、マスター局２の仮基準局送信制御手段２４ｂによる仮基準局３への校正信号送信指示を、所定時間毎に連続して行えば、スレーブ局４は、テレビ放送やラジオ放送を受信するように、任意のタイミングで校正信号を受信して周波数校正および時刻校正を行う事ができるので、利便性の高いものとなる。 Likewise, in the same manner, transmission information acquired by the master station 2 at the time of receiving the _N- 1th calibration signal for the Nth calibration signal (master station phase difference) _MN-1 and master station reception time TMN _-1 ) Will be modulated onto the carrier wave. As described later, in order to perform frequency calibration and time calibration in the slave station 4, it is sufficient if at least two consecutive calibration signals can be received, but as in the frequency calibration system 1 of this embodiment, If the calibration signal transmission instruction to the provisional reference station 3 by the provisional reference station transmission control means 24b of the master station 2 is continuously issued at predetermined time intervals, the slave station 4 can arbitrarily receive the television broadcast and the radio broadcast. Since the calibration signal can be received at the timing to perform frequency calibration and time calibration, it is highly convenient.

なお、仮基準局３より送信される校正信号が何回目であるかは、校正信号の送信情報の一つとして含ませたパケットＩＤ（例えば、連続する送信番号）によってマスター局２およびスレーブ局４で知ることができる。また、校正信号の送信情報として、マスター局２に固有の通信局ＩＤもしくは仮基準局３に固有の通信局ＩＤを含めておけば、校正のためのマスタークロック２３がどのマスター局２のものかを判定できる。例えば、マスター局２Ａの制御下にある仮基準局３Ａとマスター局２Ｂの制御下にある仮基準局３Ｂの両局から校正信号を受信できる位置にあるスレーブ局４では、仮基準局３Ａからの校正信号と仮基準局３Ｂからの校正信号とを識別できるので、何れか一方の仮基準局からの校正信号を選んで、周波数校正および時刻校正に用いることができる。 The number of times the calibration signal transmitted from the temporary reference station 3 is determined by the master station 2 and the slave station 4 according to the packet ID (for example, consecutive transmission numbers) included as one of the transmission information of the calibration signal. I can know. In addition, if the communication station ID unique to the master station 2 or the communication station ID unique to the temporary reference station 3 is included as the transmission information of the calibration signal, it is determined which master station 2 the master clock 23 for calibration belongs to. It can be determined. For example, in slave station 4 at a position where calibration signals can be received from both temporary reference station 3A under control of master station 2A and temporary reference station 3B under control of master station 2B, with calibration signals from temporary reference station 3A Since the calibration signal from the temporary reference station 3B can be identified, the calibration signal from any one of the temporary reference stations can be selected and used for frequency calibration and time calibration.

上記のようにして、第１時刻に仮基準局３より送信された校正信号を受信するスレーブ局４では、受信機４２の復調手段４２ａによって校正信号を復調する。この復調処理には、被校正クロック４３の周波数発生器４３ａで発生させた基準周波数と、時刻カウンタ４３ｂによって計時される時刻情報が用いられ、復調信号が時系列に演算処理装置４４へ入力される。なお、被校正クロック４３の時刻カウンタ４３ｂには、上述したマスタークロック２３の周波数発生器２３ａに比べて低精度の周波数発生器４３ａから計時基準周波数の信号が供給されており、このクロックをカウントすることで、時刻カウンタ４３ｂは自局内時刻を計時している。なお、時刻カウンタ４３ｂにて更新される時刻を可視表示する時刻表示器を別途設けても良い。 As described above, in the slave station 4 which receives the calibration signal transmitted from the temporary reference station 3 at the first time, the demodulation means 42a of the receiver 42 demodulates the calibration signal. In this demodulation processing, the reference frequency generated by the frequency generator 43a of the clock 43 to be calibrated and the time information clocked by the time counter 43b are used, and the demodulation signal is input to the processing unit 44 in time series. . A signal of a clock reference frequency is supplied to the time counter 43b of the clock 43 to be calibrated from the frequency generator 43a having lower accuracy than the frequency generator 23a of the master clock 23 described above, and this clock is counted. Thus, the time counter 43b counts the time within the own station. A time indicator may be separately provided to visibly display the time updated by the time counter 43b.

上記復調手段４２ａからの復調信号は、演算処理装置４４の搬送波位相および時刻取得手段４４ａに入力され、搬送波位相を取得する。この搬送波位相とは、校正信号の搬送波（仮基準局３における仮基準クロック３３の周波数発生器３３ａで発生させた基準周波数信号）と被校正クロック４３の周波数発生器４３ａで生成した基準周波数信号との位相差（以下、スレーブ局位相差ΦＳ_t1という）である。なお、この搬送波位相および時刻取得手段４４ａでは、スレーブ局４における校正信号の受信時刻（以下、スレーブ局受信時刻ＴＳ_t1という）も取得する。 The demodulated signal from the demodulation means 42a is input to the carrier wave phase of the arithmetic processing unit 44 and the time acquisition means 44a to acquire the carrier wave phase. The carrier wave phase refers to the carrier wave of the calibration signal (a reference frequency signal generated by the frequency generator 33a of the temporary reference clock 33 in the temporary reference station 3) and the reference frequency signal generated by the frequency generator 43a of the clock 43 to be calibrated. phase difference (hereinafter, referred to as slave station retardation .PHI.S _t1) is. The carrier wave phase and time acquisition means 44a also acquires the reception time of the calibration signal at the slave station 4 (hereinafter referred to as slave station reception time _Tst1 ).

このように、スレーブ局４の受信機４２と被校正クロック４３と演算処理装置４４が協働することで、「仮基準局より第１時刻ｔ１に送信された校正信号を受信して、校正信号の搬送波と被校正クロックで生成した被校正周波数信号との位相差であるスレーブ局位相差ΦＳ_t1を求めるスレーブ局位相差取得手段」としての機能と、「仮基準局より第１時刻ｔ１に送信された校正信号を受信した時刻であるスレーブ局受信時刻ＴＳ_t1を前記被校正クロックより取得するスレーブ局受信時刻取得手段」としての機能を備えるものとなる。なお、スレーブ局位相差取得手段およびスレーブ局受信時刻取得手段によるスレーブ局位相差ΦＳ_t1、スレーブ局受信時刻ＴＳ_t1の取得手法は特に限定されるものではなく、デジタル無線通信の直交変調・復調の原理を用いたデジタル処理で求めても良いし、アナログ的に求めるようにしても構わない。 As described above, the receiver 42 of the slave station 4, the clock 43 to be calibrated, and the processing unit 44 cooperate with each other to “receive the calibration signal transmitted from the temporary reference station at the first time t 1 and functions as a slave station phase difference acquiring means "for obtaining the slave station retardation .PHI.S _t1 is the phase difference between the calibration frequency signal generated by the carrier wave and the calibration clock, transmitted from the" temporary reference station to the first time t1 The slave station reception time TS _t1 which is the time when the calibration signal is received is provided as a slave station reception time acquisition means for acquiring from the clock to be calibrated. The method of acquiring the slave station phase difference SS _t1 and the slave station reception time TS _t1 by the slave station phase difference acquisition means and the slave station reception time acquisition means is not particularly limited, and the orthogonal modulation / demodulation of digital wireless communication It may be determined by digital processing using the principle, or may be determined in an analog manner.

上記搬送波位相および時刻取得手段４４ａによって取得したスレーブ局位相差ΦＳ_t1は校正位相差取得手段４４ｃに供給され、スレーブ局受信時刻ＴＳ_t1は校正時刻差取得手段４４ｄに供給される。校正位相差取得手段４４ｃおよび校正時刻差取得手段４４ｄは、それぞれスレーブ局位相差ΦＳ_t1およびスレーブ局受信時刻ＴＳ_t1を記憶しておく。 The carrier phase and time acquisition unit 44a slave station retardation .PHI.S _t1 acquired by is supplied to the calibration phase difference obtaining means 44c, the slave station receiving time TS _t1 is supplied to the calibration time difference obtaining means 44d. Calibration phase difference obtaining means 44c and calibration time difference obtaining means 44d memorizes the slave station retardation .PHI.S _t1 and slave station receiving time TS _t1 respectively.

また、復調手段４２ａにて復調された復調信号は、受信情報取得手段４４ｂへも供給され、コード化された送信情報を復号する。しかしながら、第１時刻に仮基準局３より送信された校正信号（１回目）には、変調信号としてマスター局位相差およびマスター局受信時刻が含まれていないので、１回目の校正信号受信時には、受信情報取得手段４４ｂから校正位相差取得手段４４ｃおよび校正時刻差取得手段４４ｄに供給する情報は無い。 The demodulated signal demodulated by the demodulation means 42a is also supplied to the reception information acquisition means 44b to decode the encoded transmission information. However, since the master station phase difference and the master station reception time are not included as modulation signals in the calibration signal (first time) transmitted from temporary reference station 3 at the first time, reception is performed when the first calibration signal is received. There is no information supplied from the information acquisition means 44b to the calibration phase difference acquisition means 44c and the calibration time difference acquisition means 44d.

上記第１時刻から校正信号の送受信に必要十分な時間（例えば、０．１秒）が経過した第２時刻に仮基準局３より送信された校正信号（２回目）をスレーブ局４で受信すると、搬送波位相および時刻取得手段４４ａによって取得したスレーブ局位相差ΦＳ_t2は校正位相差取得手段４４ｃに供給され、スレーブ局受信時刻ＴＳ_t2は校正時刻差取得手段４４ｄに供給されて、少なくとも次回の校正信号受信処理まで記憶保持される。 When the slave station 4 receives the calibration signal (second time) transmitted from the temporary reference station 3 at the second time when a time (for example, 0.1 second) necessary and sufficient for transmission and reception of the calibration signal has elapsed from the first time. slave station retardation .PHI.S _t2 obtained by carrier phase and time acquisition unit 44a is supplied to the calibration phase difference obtaining means 44c, the slave station receiving time TS _t2 is supplied to the calibration time difference obtaining means 44d, at least the next calibration signal Memory is held until reception processing.

加えて、２回目の校正信号には、送信情報としてマスター局位相差ΦＭ_t1およびマスター局受信時刻ＴＭ_t1が含まれているので、受信情報取得手段４４ｂによりデコードされ、マスター局情報（マスター局位相差ΦＭ_t1、マスター局受信時刻ＴＭ_t1）を取得する。すなわち、スレーブ局４の受信機４２と被校正クロック４３と演算処理装置４４が協働することで、「仮基準局より第２時刻ｔ２に送信された校正信号を受信して、仮基準局からの送信情報であるマスター局位相差ΦＭ_t1およびマスター局受信時刻ＴＭ_t1を取得するマスター局情報取得手段」としての機能を備えるものとなる。なお、マスター局位相差ΦＭ_t1は、演算処理装置４４の校正位相差取得手段４４ｃに供給され、マスター局受信時刻ＴＭ_t1は、演算処理装置４４の校正時刻差取得手段４４ｄに供給される。 In addition, since the master station phase difference マスター M _t1 and the master station reception time TM _t1 are included in the second calibration signal as transmission information, they are decoded by the reception information acquisition means 44b and master station information (master station position (master station position) The phase difference MM _t1 and the master station reception time TM _t1 ) are acquired. That is, the receiver 42 of the slave station 4, the clock 43 to be calibrated, and the processing unit 44 cooperate with each other to “receive the calibration signal transmitted from the temporary reference station at the second time t 2 and transmit from the temporary reference station It has a function as “master station information acquisition means for acquiring master station phase difference tM _t1, which is information” and master station reception time TM _t1 . The master station phase difference MM _t1 is supplied to the calibration phase difference acquisition means 44c of the arithmetic processing unit 44, and the master station reception time TM _t1 is supplied to the calibration time difference acquisition means 44d of the arithmetic processing unit 44.

校正位相差取得手段４４ｃは、スレーブ局位相差ΦＳ_t1（仮基準局３における仮基準クロック３３の周波数発生器３３ａが生成した仮基準周波数信号と、スレーブ局４における被校正クロック４３の周波数発生器４３ａが生成した被校正周波数信号との相対的な位相差）とマスター局位相差ΦＭ_t1（仮基準局３における仮基準クロック３３の周波数発生器３３ａが生成した仮基準周波数信号と、マスター局２におけるマスタークロック２３の周波数発生器２３ａが生成した基準周波数信号との相対的な位相差）との差である校正位相差ΔΦ_t1を求める。この校正位相差ΔΦ_t1は、被校正クロック４３の周波数発生器４３ａが生成する被校正周波数信号とマスタークロック２３の周波数発生器２３ａが生成する基準周波数信号との位相差である。 The calibration phase difference acquisition means 44c is a slave station phase difference ΦS _t1 (the provisional reference frequency signal generated by the frequency generator 33a of the provisional reference clock 33 in the provisional reference station 3 and the frequency generator 43a of the clock to be calibrated 43 in the slave station 4). Phase difference と M _t1 (temporary reference frequency signal generated by the frequency generator 33a of the provisional reference clock 33 in the provisional reference station 3), and the master in the master station 2 A calibration phase difference ΔΦ _t1 which is a difference between the clock 23 and the relative frequency difference between the clock 23 and the reference frequency signal generated by the frequency generator 23a is determined. The calibration phase difference ΔΦ _t1 is a phase difference between the frequency signal to be calibrated generated by the frequency generator 43a of the clock 43 to be calibrated and the reference frequency signal generated by the frequency generator 23a of the master clock 23.

この校正位相差ΔΦ_t1は周波数校正手段４４ｅへ供給される。この周波数校正手段４４ｅは、校正位相差ΔΦ_t1に基づいて被校正クロック４３の周波数発生器４３ａを制御し、周波数発生器４３ａから時刻カウンタ４３ｂに出力される計時基準周波数が、マスタークロック２３の周波数発生器２３ａが時刻カウンタ２３ｂに出力される計時基準周波数と一致するように位相ロックさせる。これにより、スレーブ局４の被校正クロック４３をマスタークロック２３並みの精度に校正することができる。 The calibration phase difference ΔΦ _t1 is supplied to the frequency calibration means 44e. The frequency calibration means 44e controls the frequency generator 43a of the clock 43 to be calibrated based on the calibration phase difference ΔΦ _t1 , and the clocking reference frequency output from the frequency generator 43a to the time counter 43b is the frequency of the master clock 23. The generator 23a is phase-locked to coincide with the clocking reference frequency output to the time counter 23b. Thus, the clock 43 to be calibrated of the slave station 4 can be calibrated to the same accuracy as the master clock 23.

また、校正時刻差取得手段４４ｄは、マスター局受信時刻ＴＭ_t1（第２時刻に仮基準局３から送信された校正信号の送信情報に含まれていた情報）とスレーブ局受信時刻ＴＳ_t1（第１時刻に搬送波位相および時刻取得手段４４ａにより取得した情報）との差である校正時刻差ΔＴ_t1を求める。 Further, the calibration time difference acquisition means 44d is configured to receive the master station reception time TM _t1 (the information included in the transmission information of the calibration signal transmitted from the temporary reference station 3 at the second time) and the slave station reception time TS _t1 (the first time A calibration time difference ΔT _t1 which is a difference between the carrier wave phase and information acquired by the time acquisition means 44a at time is calculated.

この校正時刻差ΔＴ_t1は時刻校正手段４４ｆへ供給される。この時刻校正手段４４ｆは、校正時刻差ΔＴ_t1に基づいて、被校正クロック４３の時刻カウンタ４３ｂの時刻を補正するのである。なお、仮基準局３からマスター局２までの距離と、仮基準局３からスレーブ局４までの距離が異なれば、それだけ両局の受信時刻に誤差が生じてしまうため、スレーブ局４の時刻校正手段４４ｆによって行う時刻カウンタ４３ｂに対する時刻校正を行っても、マスタークロック２３の時刻カウンタ２３ｂの時刻と完全に一致させることはできないが、十分実用的な精度での時刻校正が可能である。 The calibration time difference ΔT _t1 is supplied to the time calibration means 44f. The time correcting unit 44f, based on the calibration time difference [Delta] T _t1, is to correct the time of the time counter 43b of the calibration clock 43. If the distance from the temporary reference station 3 to the master station 2 and the distance from the temporary reference station 3 to the slave station 4 are different, an error will occur in the reception times of both stations, so the time calibration means 44f of the slave station 4 Even if time calibration is performed on the time counter 43b performed by the above method, the time can not be perfectly matched with the time of the time counter 23b of the master clock 23, but time calibration with sufficiently practical accuracy is possible.

ここで、図２を参照しつつ、スレーブ局４で行う周波数校正および時刻校正を時系列に説明する。 Here, frequency calibration and time calibration performed by the slave station 4 will be described in time series with reference to FIG.

例えば、マスター局２からの指示により、仮基準局３からＮ回目の校正信号が送信されたとき、これをスレーブ局４は第１時刻における校正信号として受信したものとする。Ｎ回目の校正信号には、送信情報としてマスター局位相差ΦＭ_N-1およびマスター局受信時刻ＴＭ_N-1が含まれており、これを受信したスレーブ局４の受信機４２は、受信情報としてマスター局位相差ΦＭ_N-1およびマスター局受信時刻ＴＭ_N-1を取得すると共に、スレーブ局位相差ΦＳ_Nおよびスレーブ局受信時刻ＴＳ_Nを取得し、これらを演算処理装置４４へ供給する。なお、スレーブ局４においては、これが最初の校正信号受信であるから、マスター局位相差ΦＭ_N-1およびマスター局受信時刻ＴＭ_N-1は使用しない。また、マスター局２では、仮基準局３からＮ回目の校正信号を受信して、マスター局位相差ΦＭ_Nおよびマスター局受信時刻ＴＭ_Nを取得しておく。 For example, when an N-th calibration signal is transmitted from the temporary reference station 3 according to an instruction from the master station 2, it is assumed that the slave station 4 receives this as a calibration signal at the first time. Master station phase difference MMN _-1 and master station reception time TMN _-1 are included in the _N- th calibration signal as transmission information, and the receiver 42 of slave station 4 that received these signals is received information as reception information acquires the master station retardation .PHI.M _N-1 and the master station receiving time TM _N-1, obtains the slave station retardation .PHI.S _N and slave station receiving time TS _N, and supplies them to the processor 44. Since the slave station 4 receives the first calibration signal, the master station phase difference MMN _-1 and the master station reception time TMN _-1 are not used. Also, the master station 2, from the temporary reference station 3 receives the calibration signal in the N-th, obtain a master station retardation .PHI.M _N and the master station receiving time TM _N.

続いて、マスター局２からの指示により、仮基準局３からＮ＋１回目の校正信号が送信されると、これをスレーブ局４は第２時刻における校正信号として受信する。Ｎ＋１回目の校正信号には、送信情報としてマスター局位相差ΦＭ_Nおよびマスター局受信時刻ＴＭ_Nが含まれており、これを受信したスレーブ局４の受信機４２は、受信情報としてマスター局位相差ΦＭ_Nおよびマスター局受信時刻ＴＭ_Nを取得すると共に、スレーブ局位相差ΦＳ_N+1およびスレーブ局受信時刻ＴＳ_N+1を取得し、これらを演算処理装置４４へ供給する。 Subsequently, when the N + 1th calibration signal is transmitted from the temporary reference station 3 according to an instruction from the master station 2, the slave station 4 receives this as a calibration signal at the second time. The N + 1-th calibration signal, includes master station retardation .PHI.M _N and the master station receiving time TM _N is a transmission information, the receiver 42 of the slave station 4 which received the message, the master station phase difference as the received information acquires the .PHI.M _N and the master station receiving time TM _N, acquires the slave station retardation .PHI.S N _{+ 1} and the slave station receiving time TS N _{+ 1,} and supplies them to the processor 44.

演算処理装置４４では、Ｎ回目の校正信号受信時に受け取ったスレーブ局位相差ΦＳ_Nおよびスレーブ局受信時刻ＴＳ_Nと、今回（Ｎ＋１回目）に受け取ったマスター局位相差ΦＭ_Nおよびマスター局受信時刻ＴＭ_Nに基づいて、校正位相差ΔΦ_Nと校正時刻差ΔＴ_Nを求める。ここで、Ｎ回目の校正信号受信時に求めた校正位相差ΔΦ_N＝ΦＳ_N−ΦＭ_N、Ｎ回目の校正信号受信時に求めた校正時刻差ΔＴ_N＝ＴＳ_N−ＴＭ_N、である。 In the arithmetic processing unit 44, N-th calibration signal received during the slave station retardation .PHI.S _N and the slave station receives the received time TS _N and this time master station phase difference received the (N + 1 th) .PHI.M _N and the master station receiving time TM Based on _N , a calibration phase difference ΔΦ _N and a calibration time difference ΔT _N are determined. Here, a calibration time difference [Delta] T _N = TS _N -TM _N, determined in the calibration phase difference ΔΦ _{_{_N}} = ΦS _N -ΦM _N, during calibration signal reception of N th determined during calibration signal reception of N th.

続いて、マスター局２からの指示により、仮基準局３からＮ＋２回目の校正信号が送信されると、これをスレーブ局４は３回目の送信信号として受信する。Ｎ＋２回目の校正信号には、送信情報としてマスター局位相差ΦＭ_N+1およびマスター局受信時刻ＴＭ_N+1が含まれており、これを受信したスレーブ局４の受信機４２は、受信情報としてマスター局位相差ΦＭ_N+1およびマスター局受信時刻ＴＭ_N+1を取得すると共に、スレーブ局位相差ΦＳ_N+2およびスレーブ局受信時刻ＴＳ_N+2を取得し、これらを演算処理装置４４へ供給する。 Subsequently, when the N + 2th calibration signal is transmitted from the temporary reference station 3 according to an instruction from the master station 2, the slave station 4 receives this as a third transmission signal. The N + 2-th calibration signal, and the master station retardation .PHI.M N _{+ 1} and the master station receives the time TM N _{+ 1} is included as the transmission information, the receiver 42 of the slave station 4 which received this, as the reception information The master station phase difference MMN _{+ 1} and the master station reception time TMN _{+ 1} are acquired, and the slave station phase difference ΦSN _{+ 2} and the slave station reception time TSN _{+ 2} are acquired, and these are sent to the arithmetic processing unit 44 Supply.

演算処理装置４４では、Ｎ＋１回目の校正信号受信時に受け取ったスレーブ局位相差ΦＳ_N+1およびスレーブ局受信時刻ＴＳ_N+1と、今回（Ｎ＋２回目）に受け取ったマスター局位相差ΦＭ_N+1およびマスター局受信時刻ＴＭ_N+1に基づいて、校正位相差ΔΦ_N+1と校正時刻差ΔＴ_N+1を求める。ここで、Ｎ＋１回目の校正信号受信時に求めた校正位相差ΔΦ_N+1＝ΦＳ_N+1−ΦＭ_N+1、Ｎ＋１回目の校正信号受信時に求めた校正時刻差ΔＴ_N+1＝ＴＳ_N+1−ＴＭ_N+1、である。 In the arithmetic processing unit 44, N + 1 th calibration signal receiving slave station phase difference received when .PHI.S N _{+ 1} and the slave station receiving time TS N _{+ 1} of this master station phase difference received the (N + 2-th) .PHI.M N _{+ 1} The calibration phase difference Δ 受信_{N + 1} and the calibration time difference ΔT _{N + 1} are determined based on the master station reception time TM _{N + 1} . Here, the calibration phase difference ΔΦ _{N + 1} = Φ S _{N + 1} −Φ M _{N + 1} obtained when the _{N +} 1th calibration signal is received, and the calibration time difference ΔT _{N + 1} = TS _{N +} obtained when the N + 1 calibration signal is received _{It is 1-} TMN _{+ 1} .

上述したように、本実施形態に係る周波数校正システム１によれば、マスター局２の制御によって仮基準局３より連続的に校正信号を送信させるので、スレーブ局４は、被校正クロック４３で生成される被校正周波数とマスタークロック２３で生成される基準周波数との位相差である校正位相差ΔΦを簡便に得ることができ、仮基準局３からの伝搬時間が変動しなければ、被校正クロック４３の被校正周波数をマスタークロック２３の基準周波数と同等精度に校正することが可能となる。しかも、スレーブ局４が校正位相差ΔΦを求めるために必要なマスター局２側の情報（マスター局位相差ΦＭ_t1およびマスター局受信時刻ＴＭ_t1）を、校正信号によって送ることができるので、マスター局２側の情報をマスター局２からスレーブ局４へ送るための通信手段を別途設ける必要がない点でも利便性が高い。よって、低コストで利便性の高い周波数校正システムを構築できる。 As described above, according to the frequency calibration system 1 according to the present embodiment, the calibration signal is continuously transmitted from the temporary reference station 3 under the control of the master station 2, so that the slave station 4 is generated by the clock 43 to be calibrated. Calibration phase difference .DELTA..PHI., Which is the phase difference between the frequency to be calibrated and the reference frequency generated by the master clock 23, can be obtained simply, and if the propagation time from the temporary It is possible to calibrate the frequency to be calibrated to the same accuracy as the reference frequency of the master clock 23. Moreover, since the master station 2 side information (master station phase difference MM _t1 and master station reception time TM _t1 ) necessary for the slave station 4 to obtain the calibration phase difference ΔΦ can be sent by the calibration signal, the master station Convenience is also high in that there is no need to separately provide a communication means for sending information on the 2 side from the master station 2 to the slave station 4. Therefore, it is possible to construct a low-cost and highly convenient frequency calibration system.

また、周波数校正システム１において、マスター局２とスレーブ局４とは、クロック精度による相対的な関係において定まるもので、マスター局２のマスタークロック２３並みに高精度に校正された被校正クロック４３を持つスレーブ局４をマスター局として機能させることも可能である。例えば、スレーブ局４の制御下におかれるサブ仮基準局を設けておき、マスター局２の制御下におかれる仮基準局３からの校正信号によって周波数校正・時刻校正を行ったスレーブ局４が、サブ仮基準局からサブ校正信号を送信すれば、このサブ校正信号を受信可能なサブスレーブ局では、スレーブ局４の被校正クロック４３を基準とする周波数校正・時刻校正が可能となる。 Further, in the frequency calibration system 1, the master station 2 and the slave station 4 are determined by the relative relationship based on the clock accuracy, and the clock 43 to be calibrated that has been calibrated with high accuracy as the master clock 23 of the master station 2 is It is also possible to make the slave station 4 possessed to function as a master station. For example, a slave station 4 that has been provided with a sub temporary reference station under control of slave station 4 and has performed frequency calibration and time calibration by a calibration signal from temporary reference station 3 under control of master station 2 By transmitting the sub calibration signal from the temporary reference station, the sub slave station capable of receiving the sub calibration signal can perform frequency calibration and time calibration based on the clock 43 to be calibrated of the slave station 4.

加えて、本実施形態に係る周波数校正システム１によれば、スレーブ局４の被校正クロック４３の時刻をマスター局２のマスタークロック２３並みの時刻に校正できる。なお、時刻校正手段４４ｆは、被校正クロック４３の周波数発生器４３ａにより生成される計時基準周波数をマスタークロック２３の周波数発生器２３ａにより生成される計時基準周波数に一致するように位相ロックしたうえで、予め定めた時刻補正実行条件が達成されるまで校正時刻差取得手段４４ｄより校正時刻差ΔＴを複数回に亘って取得し、それら校正時刻差ΔＴの平均値で被校正クロックの時刻を補正するようにしても良い。すなわち、校正時刻差ΔＴを取得する度に時刻カウンタ４３ｂを補正せずに、補正が必要と考えられるタイミングでのみ時刻校正を行うのである。これは、スレーブ局４において、被校正クロック４３の周波数発生器４３ａにより生成される計時基準周波数がマスタークロック２３の周波数発生器２３ａにより生成される計時基準周波数に一致するように位相ロックしているため、スレーブ局４の時刻とマスター局２の時刻とに生ずるズレを、極めて微少な値に抑えられるからである。なお、時刻補正実行条件は、校正時刻差ΔＴの取得回数が６００回（約１分）に達することや、校正時刻差ΔＴの平均値が時刻カウンタ４３ｂのクロックアップ間隔を超えたタイミング、校正時刻差ΔＴの平均値の分散が所定の値以下になったタイミング等である。 In addition, according to the frequency calibration system 1 according to the present embodiment, the time of the clock 43 to be calibrated of the slave station 4 can be calibrated to the same time as the master clock 23 of the master station 2. The time calibration means 44f performs phase locking so that the clocking reference frequency generated by the frequency generator 43a of the clock 43 to be calibrated matches the clocking reference frequency generated by the frequency generator 23a of the master clock 23. The calibration time difference ΔT is acquired multiple times from the calibration time difference acquisition means 44d until a predetermined time correction execution condition is achieved, and the time of the clock to be calibrated is corrected with the average value of the calibration time differences ΔT. You may do so. That is, each time the calibration time difference ΔT is acquired, the time calibration is performed only at the timing when the correction is considered to be necessary, without correcting the time counter 43b. This is phase-locked in the slave station 4 so that the clocking reference frequency generated by the frequency generator 43a of the clock 43 to be calibrated matches the clocking reference frequency generated by the frequency generator 23a of the master clock 23. Therefore, the difference between the time of the slave station 4 and the time of the master station 2 can be suppressed to a very small value. The time correction execution condition is that the number of times of acquisition of the calibration time difference ΔT reaches 600 times (about 1 minute), the timing when the average value of the calibration time difference ΔT exceeds the clock-up interval of the time counter 43b, calibration time This is timing or the like when the variance of the average value of the difference ΔT becomes equal to or less than a predetermined value.

また、スレーブ局４の時刻校正手段４４ｆは、校正時刻差ΔＴから計時基準周波数の逆数（１周期長）の整数倍となる粗調整時刻差ΔＴｃと、計時基準周波数の逆数（１周期長）に満たない微調整時刻差ΔＴｆとを求め、粗調整時刻差ΔＴｃに基づいて被校正クロック４３の時刻カウンタ４３ｂを校正し、微調整時刻差ΔＴｆを計時基準周波数信号との位相差に換算した時刻微調整位相差ΔΦｆを求めるようにしても良い。この時刻微調整位相差ΔΦｆを周波数校正手段４４ｅへ供給すると、周波数校正手段４４ｅが時刻微調整位相差ΔΦｆに基づいて、位相ロックポイントを修正する。すなわち、時刻カウンタ４３ｂに対する時刻校正は粗調整時刻差ΔＴｃにより粗調整し、それでは調整しきれない微調整時刻差ΔＴｆを周波数発生器４３ａの位相をマスター周波数発生器２３ａに対してΔΦｆだけずらすことによって微調整するのである。このように、時刻校正手段４４ｆと周波数校正手段４４ｅとが協働して時刻校正を行うと、一層高精度の時刻合わせが可能となる。なお、微調整位相差ΔΦｆが２πを超える値を取る場合には、一度にずらすのではなく、２πよりも十分に小さい値に分けて、その小さい値ずつロックし直すことを繰り返せば、２πを超える微調整位相差ΔΦｆ分の微調整が可能になる。 In addition, the time calibration means 44f of the slave station 4 changes the correction time difference ΔT to a coarse adjustment time difference ΔTc which is an integral multiple of the reciprocal of the clocking reference frequency (one cycle length) and the reciprocal of the clocking reference frequency (one cycle length). A fine adjustment time difference ΔTf that does not satisfy is obtained, the time counter 43b of the clock 43 to be calibrated is calibrated based on the coarse adjustment time difference ΔTc, and the fine adjustment time difference ΔTf is converted to a phase difference with the time reference frequency signal The adjusted phase difference ΔΦf may be determined. When the time fine adjustment phase difference ΔΦf is supplied to the frequency calibration means 44e, the frequency calibration means 44e corrects the phase lock point based on the time fine adjustment phase difference ΔΦf. That is, the time calibration with respect to the time counter 43b is roughly adjusted by the rough adjustment time difference ΔTc, and by shifting the phase of the fine adjustment time difference ΔTf which can not be adjusted with that of the frequency generator 43a by ΔΦ f with respect to the master frequency generator 23a. Fine-tune. As described above, when the time calibration means 44f and the frequency calibration means 44e cooperate with each other to perform time calibration, it is possible to perform time adjustment with higher accuracy. If the fine adjustment phase difference ΔΦ f takes a value exceeding 2π, dividing it into a value sufficiently smaller than 2π instead of shifting it at once, and repeating the locking again by the smaller value, 2π is obtained. Fine adjustment can be performed by the amount of fine adjustment phase difference ΔΦ f that exceeds.

以上、本発明に係る周波数校正システムを実施形態に基づき説明したが、本発明は、この実施形態のみに限定されるものではなく、特許請求の範囲に記載の構成を変更しない限りにおいて実現可能な全ての周波数校正システムを権利範囲として包摂するものである。 As mentioned above, although the frequency calibration system concerning the present invention was explained based on an embodiment, the present invention is not limited only to this embodiment, and it is realizable unless the composition of a statement is changed. All frequency calibration systems are included in the scope of rights.

１周波数校正システム
２マスター局
２１アンテナ
２２受信機
２２ａ復調手段
２３マスタークロック
２３ａ周波数発生器
２３ｂ時刻カウンタ
２４演算処理装置
２４ａ搬送波位相および時刻取得手段
２４ｂ仮基準局送信制御手段
３仮基準クロック
３１アンテナ
３２送信機
３２ａ校正信号送信手段
３３仮基準クロック
３３ａ周波数発生器
４ａ〜４ｄ第１〜第４スレーブ局
４１アンテナ
４２受信機
４２ａ復調手段
４３被校正クロック
４３ａ周波数発生器
４３ｂ時刻カウンタ
４４演算処理装置
４４ａ搬送波位相および時刻取得手段
４４ｂ受信情報取得手段
４４ｃ校正位相差取得手段
４４ｂ校正時刻差取得手段
４４ｅ周波数校正手段
４４ｆ時刻校正手段 DESCRIPTION OF SYMBOLS 1 frequency calibration system 2 master station 21 antenna 22 receiver 22a demodulation means 23 master clock 23a frequency generator 23b time counter 24 arithmetic processing unit 24a carrier wave phase and time acquisition means 24b provisional reference station transmission control means 3 provisional reference clock 31 antenna 32 transmission Machine 32a Calibration signal transmission means 33 Temporary reference clock 33a Frequency generator 4a to 4d 1st to 4th slave stations 41 Antenna 42 Receiver 42a Demodulation means 43 Clock to be calibrated 43a Frequency generator 43b Time counter 44 Arithmetic processing unit 44a Carrier phase And time acquisition means 44b reception information acquisition means 44c calibration phase difference acquisition means 44b calibration time difference acquisition means 44e frequency calibration means 44f time calibration means

Claims

A master station that performs wireless communication using a master clock provided with a frequency generator that generates a signal with a high precision clocking reference frequency that can be a clock reference;
A provisional reference station having a provisional reference clock provided with a frequency generator for generating a communication frequency signal of its own station, and transmitting a calibration signal in which required transmission information is carried on a carrier wave generated by the provisional reference clock;
The clock to be calibrated is provided with a frequency generator for generating a signal of a clock reference frequency used as a reference of the local clock, and a calibration signal from the temporary reference station is received, and the clock reference frequency of the clock to be calibrated is One or more slave stations that are calibrated to the clocking reference frequency;
A frequency calibration system consisting of
The master station
Master station phase difference acquisition to obtain a master station phase difference MM _t1 which is the phase difference between the carrier wave of the calibration signal and the reference frequency signal generated by the master clock by receiving the calibration signal transmitted from the temporary reference station at the first time t1 Means,
Provisional reference station transmission instructing the temporary reference station to transmit a calibration signal including the master station phase difference MM _t1 as transmission information at a second time t2 when a time sufficient for transmission and reception of a calibration signal has elapsed from the first time t1. Control means,
Provide
The temporary reference station
Calibration signal transmitting means for transmitting a calibration signal in which transmission information is placed on the carrier wave of the provisional reference frequency generated by the provisional reference clock based on the transmission instruction from the master station;
Provide
The slave station
A slave station which receives a calibration signal transmitted from the temporary reference station at a first time t1 and obtains a slave station phase difference SS _t1 which is a phase difference between a carrier of the calibration signal and a frequency signal to be calibrated generated by the clock to be calibrated. Phase difference acquisition means,
Master station information acquisition means for receiving a calibration signal transmitted from the temporary reference station at the second time t2 and acquiring a master station phase difference MM _t1 which is transmission information from the temporary reference station;
The temporary by reference clock and the temporary reference frequency signal and the slave station retardation .PHI.S _t1 is the phase difference between the calibration signals by the object to be calibrated clock, like the reference frequency signal by the temporary reference frequency signal and the master clock by the temporary reference clock Calibration phase difference acquisition to obtain calibration phase difference ΔΦ _t1 which is the phase difference between the frequency signal to be calibrated by the clock to be calibrated and the reference frequency signal by the master clock by finding the difference from the master station phase difference MM _t1 which is the phase difference Means,
Frequency calibration means for phase locking such that the clocking reference frequency of the clock to be calibrated becomes the clocking reference frequency of the master clock based on the calibration phase difference ΔΦ _t1 acquired by the calibration phase difference acquiring means;
A frequency calibration system characterized in that

The frequency calibration system according to claim 1, wherein the calibration signal transmission instruction to the provisional reference station by the provisional reference station transmission control means of the master station is continuously performed at predetermined time intervals.

The frequency calibration system according to claim 1 or 2, wherein the calibration signal transmission instruction from the temporary reference station transmission control means of the master station to the temporary reference station is performed by direct communication by wire.

The master station is provided with master station reception time acquisition means for acquiring from the master clock a master station reception time TM _t1 which is a time when the calibration signal transmitted from the temporary reference station at the first time t1 is received, the temporary reference station The transmission control means instructs the temporary reference station as the transmission information of the master station phase difference MM _t1 and the master station reception time TM _t1 .
The slave station
A slave station reception time acquisition unit that acquires, from the clock to be calibrated, a slave station reception time TS _t1 that is a time when the calibration signal transmitted from the temporary reference station at the first time t1 is received;
The difference between the master station reception time TM _t1 acquired by the master station information acquisition means from the calibration signal transmitted from the temporary reference station at the second time t2 and the slave station reception time TS _t1 acquired by the slave station reception time acquisition means Calibration time difference acquisition means for obtaining a calibration time difference ΔT _t1 ;
Time calibration means for correcting the time counter of the clock to be calibrated based on the calibration time difference ΔT _t1 acquired by the calibration time difference acquisition means;
The frequency calibration system according to any one of claims 1 to 3, wherein

The time calibration means of the slave station acquires the calibration time difference ΔT a plurality of times until the predetermined time correction execution condition is achieved, and corrects the time of the clock to be calibrated with an average value that is the average thereof. The frequency calibration system according to claim 4, characterized in that:

The time calibration means of the slave station obtains a rough adjustment time difference ΔTc which is an integral multiple of the reciprocal of the clocking reference frequency from the calibration time difference ΔT, and a fine adjustment time difference ΔTf which does not satisfy the reciprocal of the clocking reference frequency. The time counter of the clock to be calibrated is calibrated based on the time difference ΔTc, and the time fine adjustment phase difference Δff obtained by converting the fine adjustment time difference ΔTf to the phase difference with the time reference frequency signal is determined and supplied to the frequency calibration means ,
The frequency calibration means of the slave station is configured to correct the phase lock point based on the time fine adjustment phase difference ΔΦ f supplied from the time calibration means. Frequency calibration system.