JP2001028556A - Demodulating device for signal undergoing spectrum spread - Google Patents

Demodulating device for signal undergoing spectrum spread

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Publication number
JP2001028556A
JP2001028556A JP11198690A JP19869099A JP2001028556A JP 2001028556 A JP2001028556 A JP 2001028556A JP 11198690 A JP11198690 A JP 11198690A JP 19869099 A JP19869099 A JP 19869099A JP 2001028556 A JP2001028556 A JP 2001028556A
Authority
JP
Japan
Prior art keywords
correlation value
value
frequency
oscillator
spreading code
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
JP11198690A
Other languages
Japanese (ja)
Inventor
Kenichi Kojimoto
賢一 柑本
Katsumi Sakata
克己 阪田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Denso Ten Ltd
Original Assignee
Denso Ten Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Denso Ten Ltd filed Critical Denso Ten Ltd
Priority to JP11198690A priority Critical patent/JP2001028556A/en
Publication of JP2001028556A publication Critical patent/JP2001028556A/en
Withdrawn legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To expand allowable range of an oscillation frequency to be mixed with a carrier frequency and to detect a correlation value peak in a short time. SOLUTION: A code synchronous circuit 13 of a demodulating device provided with a demodulation circuit 30, having a diffusion code generator 4 for a diffusion code which is the same as a diffusion code in a received signal, the code synchronous circuit 13 for the diffusion signal in the received signal and a generated diffusion code and an inverse diffusion circuit 14 for a received signal using a synchronized diffusion code, is also provided with correlators 3A and 3B taking a correlation value between the diffusion code in the received signal and the generated diffusion code. The correlators 3A and 3B consist of a division circuit for a diffusion code, which divides one cycle of a diffusion code into a plurality of parts in calculating a correlation value, an absolute value operation circuit for calculating the also lute value of the correlation value of each divided section and an addition circuit for adding the absolute value of each divided section for one cycle of the diffusion code. A carrier frequency generator 2 generates an oscillation frequency, matching with the carrier frequency of the received signal by observing the added correlation values.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明はスペクトラム拡散さ
れた信号の復調装置に関し、特に、スペクトラム通信方
式の受信機において、スペクトラム拡散された信号に含
まれている拡散符号と受信機側で発生した拡散符号の同
期をとって信号を復調する復調装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a demodulator for a spread spectrum signal, and more particularly, to a spread code included in a spread spectrum signal and a spread code generated on the receiver side in a spectrum communication type receiver. The present invention relates to a demodulator for demodulating a signal by synchronizing codes.

【０００２】[0002]

【従来の技術】従来、広帯域信号を搬送波として、元の
信号に比べて遙に帯域の広い信号に変換する変調方式は
スペクトラム拡散方式と呼ばれている。スペクトラム拡
散技術は、その秘匿性と耐妨害性によって軍事利用を目
的に発展してきた。スペクトラム拡散を用いることによ
り、干渉波や妨害波から通信を守り、通信中も雑音に紛
れて通信の事実さえも秘匿できるために軍事利用され、
レーダやＧＰＳ(GlobalPositioning System) にも利用
されている。ところが近年、このスペクトラム拡散技術
がＣＤＭＡ(Code Division Multiple Access) 方式の携
帯電話やＧＰＳを利用したナビゲーションシステム等の
商業目的に利用され始めている。2. Description of the Related Art Conventionally, a modulation method of converting a wideband signal into a signal having a much wider band than an original signal using a carrier wave is called a spread spectrum method. Spread spectrum technology has been developed for military use due to its confidentiality and immunity. By using spread spectrum, it is used for military purposes because it protects communication from interfering waves and interfering waves and can hide even the fact of communication even during communication due to noise.
It is also used for radar and GPS (Global Positioning System). However, in recent years, this spread spectrum technique has begun to be used for commercial purposes such as a CDMA (Code Division Multiple Access) type mobile phone and a navigation system using GPS.

【０００３】このようなスペクトラム拡散方式における
広帯域搬送波としては、正弦波に擬似ランダム系列を乗
積したもの（直接スペクトル拡散法）と、多数の周波数
の異なる正弦波を多値擬似ランダム系列のパターンに従
って次々に切り換えるもの（周波数ホッピング法）が知
られている。図１は直接スペクトル拡散方式の送受信機
の構成を示すものである。送信機２０は、搬送波生成部
２１、情報変調部２２、拡散符号生成部２３、拡散変調
部２４、無線部２５、及び送信アンテナ２６を備えてい
る。また、受信機１０は、受信アンテナ１１、無線部１
２、符号同期回路１３、逆拡散部（符号復調器）１４、
情報帯域バンドパスフィルタ（ＢＰＦ）１５、及び情報
復調部１６を備えている。As the broadband carrier in such a spread spectrum system, a sine wave multiplied by a pseudo-random sequence (direct spread spectrum method) and a large number of sine waves having different frequencies according to a pattern of a multi-valued pseudo random sequence are used. One that switches one after another (frequency hopping method) is known. FIG. 1 shows the configuration of a transceiver of the direct spread spectrum system. The transmitter 20 includes a carrier generation unit 21, an information modulation unit 22, a spread code generation unit 23, a spread modulation unit 24, a radio unit 25, and a transmission antenna 26. The receiver 10 includes a receiving antenna 11, a radio unit 1
2, code synchronization circuit 13, despreading unit (code demodulator) 14,
An information band pass filter (BPF) 15 and an information demodulation unit 16 are provided.

【０００４】直接スペクトル拡散方式では、伝送すべき
情報信号は送信器２０の搬送波生成部２１からの搬送波
によって情報変調部２２で情報変調された後、拡散変調
部２４に入力される。拡散変調部２４では、拡散符号生
成部２３で生成された情報信号の帯域幅に比べて十分に
広い帯域幅を持つ拡散符号を直接乗算する拡散変調が行
われることで、信号帯域幅の広帯域化が行われている。
拡散変調された信号は無線部２５と送信アンテナ２６を
通じて送信される。送信信号は、搬送波と拡散符号とデ
ータを含んでいる。In the direct spread spectrum system, an information signal to be transmitted is modulated by a carrier wave from a carrier generation unit 21 of a transmitter 20 by an information modulation unit 22 and then input to a spread modulation unit 24. The spread modulator 24 performs spread modulation by directly multiplying a spread code having a bandwidth sufficiently larger than the bandwidth of the information signal generated by the spread code generator 23, thereby increasing the signal bandwidth. Has been done.
The spread modulated signal is transmitted through a radio unit 25 and a transmission antenna 26. The transmission signal includes a carrier, a spreading code, and data.

【０００５】拡散符号生成部２３で生成される拡散符号
は、自己相関および相互相関特性の優れた系列が要求さ
れる。拡散符号の例としては、擬似雑音符号やバーカー
符号等があげられる。図１にはバーカー符号の例が示さ
れている。一方、受信機１０ではまず、スペクトラム拡
散された信号が受信アンテナ１１と無線部１２とで受信
され、この受信信号は符号同期回路１３と逆拡散部１４
に入力される。符号同期回路１３には送信機２０側の拡
散符号生成部２３で生成されて受信信号に含まれる拡散
符号と同じ拡散符号を発生する拡散符号の発生器があ
り、発生された拡散符号と受信信号に含まれる拡散信号
の同期がとられる。同期がとれた拡散符号は符号同期回
路１３から逆拡散部１４に入力される。逆拡散部１４で
は送信側と同一でかつ同期した拡散符号を受信信号に乗
算することによって、受信信号から拡散符号を取り除く
操作が行われる。[0005] The spreading code generated by the spreading code generator 23 is required to have a sequence having excellent auto-correlation and cross-correlation characteristics. Examples of spreading codes include pseudo-noise codes and Barker codes. FIG. 1 shows an example of the Barker code. On the other hand, in the receiver 10, first, the spectrum-spread signal is received by the receiving antenna 11 and the radio unit 12, and the received signal is transmitted to the code synchronization circuit 13 and the despreading unit 14.
Is input to The code synchronizing circuit 13 has a spread code generator that generates the same spread code as the spread code generated in the spread code generator 23 of the transmitter 20 and included in the received signal. Are synchronized. The synchronized spreading code is input from the code synchronization circuit 13 to the despreading unit 14. The despreading unit 14 performs an operation of removing the spread code from the received signal by multiplying the received signal by the same and synchronized spread code as the transmitting side.

【０００６】なお、受信信号中に含まれる搬送波は、受
信機１０側に設けられた局部発振器によって発振された
搬送波と同一周波数の信号を、受信信号に混合すること
によって取り除かれる。このため、受信器１０の逆拡散
部１４の前段あるいは後段には局部発振器からの信号を
受信信号に混合するミキサがあるが、図１にはこれは図
示していない。The carrier contained in the received signal is removed by mixing a signal having the same frequency as the carrier oscillated by the local oscillator provided in the receiver 10 into the received signal. For this reason, a mixer for mixing the signal from the local oscillator with the received signal is provided before or after the despreading unit 14 of the receiver 10, but this is not shown in FIG.

【０００７】このようにして受信信号から搬送波と拡散
符号が取り除かれて残った情報信号は、情報帯域バンド
パスフィルタ１５を通り、情報復調部１６で復調されて
情報信号となる。スペクトラム拡散で送られてきた信号
の復調について更に詳しく説明すると、復調に際して
は、受信信号に含まれている拡散符号の位相に合わせて
受信機１０側で拡散符号を乗じる必要がある。これは、
拡散符号が同期しているか否かを知るためには、送られ
てきた信号の拡散符号と受信機１０の拡散符号発生部１
３で発生させた拡散符号との相関値をとる必要があるか
らである。ここでいう相関値とは、受信信号に含まれて
いる拡散符号の位相と、受信機側で発生した拡散符号の
位相の一致の程度を示す量である。[0007] The information signal remaining after removing the carrier and the spread code from the received signal passes through the information band pass filter 15 and is demodulated by the information demodulation unit 16 to become an information signal. The demodulation of a signal transmitted by spread spectrum will be described in more detail. Upon demodulation, it is necessary to multiply the demodulated signal by the receiver 10 in accordance with the phase of the spread code included in the received signal. this is,
In order to know whether or not the spread codes are synchronized, the spread code of the transmitted signal and the spread code generation unit 1 of the receiver 10 are determined.
This is because it is necessary to take a correlation value with the spreading code generated in step 3. The correlation value here is an amount indicating the degree of coincidence between the phase of the spread code included in the received signal and the phase of the spread code generated on the receiver side.

【０００８】従って、受信信号に含まれる拡散符号の種
類および位相と、受信機１０側で発生した拡散符号の種
類および位相とが一致していれば相関値は高くなるが、
ずれている場合には相関値は低くなる。従って、スペク
トラム拡散通信では、拡散符号発生部１３においてスペ
クトラム拡散で送られてきた信号を復調する際に相関値
が高いポイントを探す、相関値ピーク検出の作業が必要
となる。Accordingly, if the type and phase of the spreading code included in the received signal and the type and phase of the spreading code generated on the receiver 10 side match, the correlation value increases,
In the case of deviation, the correlation value becomes low. Therefore, in the spread spectrum communication, when demodulating the signal transmitted by the spread spectrum in the spread code generation unit 13, it is necessary to search for a point having a high correlation value, and to detect a correlation value peak.

【０００９】相関値ピーク検出の作業の手順としては、
まず、搬送波周波数、拡散符号の位相を決め、拡散符号
の１周期にわたって相関を求めて相関値を得ることが行
われる。相関値が予め決めておいたスレショルドより低
ければ、拡散符号の位相をシフトさせて相関値を再び求
める作業が行われる。拡散符号１周期にわたって位相を
シフトさせて相関値を求めたのにもかかわらずピークが
検出できない場合は、搬送波の周波数を変えて再び同じ
作業が、相関値があるスレショルドを越えるまで続けら
れる。The procedure for detecting the correlation value peak is as follows.
First, the carrier frequency and the phase of the spreading code are determined, and the correlation is obtained over one cycle of the spreading code to obtain a correlation value. If the correlation value is lower than a predetermined threshold, the operation of shifting the phase of the spreading code to obtain the correlation value again is performed. If the correlation value is obtained by shifting the phase over one cycle of the spreading code and no peak is detected, the same operation is repeated again by changing the frequency of the carrier until the correlation value exceeds a certain threshold.

【００１０】このようなスペクトラム拡散通信における
拡散符号の位相を変化させて相関値のピークを求める方
法はスライディングサーチ方式と呼ばれ、例えば、特開
平９−２３２９９５号公報にその開示がある。A method of changing the phase of the spread code in such spread spectrum communication to obtain the peak of the correlation value is called a sliding search method, which is disclosed in, for example, Japanese Patent Application Laid-Open No. 9-232995.

【００１１】[0011]

【発明が解決しようとする課題】しかしながら、前述の
ようなスライディングサーチ方式では、搬送波周波数と
受信機内部で発生した周波数との誤差がある程度の範囲
内に収まっていないと、相関値のピークが検出できない
という問題点があった。このため、従来のスライディン
グサーチ方式では、受信機側において搬送波周波数を変
化させるステップを細かくする必要があり、相関値のピ
ークの検出に時間がかかるという問題点があった。However, in the above-described sliding search system, if the error between the carrier frequency and the frequency generated inside the receiver is not within a certain range, the peak of the correlation value is detected. There was a problem that it was not possible. For this reason, in the conventional sliding search method, it is necessary to make the step of changing the carrier frequency on the receiver side fine, and there is a problem that it takes time to detect the peak of the correlation value.

【００１２】この問題点を図２を用いて説明する。従来
の相関値検出方法では、図２に示すように、受信信号の
拡散符号と受信機側で容易した拡散符号の１周期の区間
で両者を比較し、比較結果を加算することで相関値をと
っていた。即ち、受信信号中の拡散符号を第１のシフト
レジスタ１７に入れ、拡散符号発生器４Ａで発生させた
拡散符号を位相シフタ４Ｂで位相を決めて第２のシフト
レジスタ１８に入れ、第１のシフトレジスタ１７に存在
する拡散符号と第２のシフトレジスタ１８に存在する拡
散符号の比較結果を加算器１９で加算して相関値をとっ
ていた。そして、相関値が小さい場合は、位相シフタ４
Ｂで拡散符号の位相をシフトしたものを第２のシフトレ
ジスタ１８に入れて同様の比較を行って相関値をとると
いう処理を拡散符号の１周期にわたって行っていた。This problem will be described with reference to FIG. In the conventional correlation value detection method, as shown in FIG. 2, the spread code of the received signal is compared with the spread code facilitated by the receiver in one cycle section, and the correlation value is obtained by adding the comparison results. I was taking. That is, the spread code in the received signal is put into the first shift register 17, the spread code generated by the spread code generator 4A is determined in phase by the phase shifter 4B and put into the second shift register 18, and the first shift register 18 The comparison result of the spreading code existing in the shift register 17 and the spreading code existing in the second shift register 18 is added by an adder 19 to obtain a correlation value. When the correlation value is small, the phase shifter 4
The process of shifting the phase of the spread code in B and putting it into the second shift register 18 and performing a similar comparison to obtain a correlation value has been performed over one cycle of the spread code.

【００１３】ところが、この方法では、搬送波周波数と
受信機の発振周波数との間に周波数ずれΔｆが存在する
と、周波数ずれΔｆの周波数で復調された拡散符号にビ
ートが生じてしまう。このため、拡散符号の１周期の期
間中にビートにより復調された拡散符号の正負が入れ代
わり、たとえ拡散符号の位相が合っていても、相関値が
低いものとなることがある。このために、相関値のピー
クを検出するためには、受信機の発振周波数をビートの
期間が十分長くなるように、搬送波周波数に十分に近づ
ける必要があった。そのため、同期サーチ時には発振周
波数を細かく変化させていく必要があった。However, in this method, if there is a frequency shift Δf between the carrier frequency and the oscillation frequency of the receiver, a beat occurs in the spread code demodulated at the frequency of the frequency shift Δf. For this reason, the sign of the spread code demodulated by the beat during one period of the spread code is switched, and even if the phase of the spread code matches, the correlation value may be low. Therefore, in order to detect the peak of the correlation value, it is necessary to bring the oscillation frequency of the receiver sufficiently close to the carrier frequency so that the period of the beat becomes sufficiently long. Therefore, it was necessary to finely change the oscillation frequency during the synchronous search.

【００１４】そこで、本発明は、前記従来のスライディ
ングサーチ方式の有する課題と解消し、受信機側で発生
する搬送波周波数の許容範囲が広く、相関値ピークを短
い時間で検出することができるスペクトラム拡散された
信号の復調装置を提供することを目的としている。Therefore, the present invention solves the problems of the conventional sliding search system, and has a wide allowable range of carrier frequencies generated on the receiver side, and can detect a correlation value peak in a short time. It is an object of the present invention to provide a demodulation device for a signal obtained.

【００１５】[0015]

【課題を解決するための手段】前記目的を達成する本発
明の特徴は、以下に第１から第９の発明として示され
る。第１の発明の構成上の特徴は、スペクトラム拡散さ
れた信号を受信して復調する復調装置であって、受信信
号に含まれる拡散符号と同じ拡散符号を発生する拡散符
号の発生器と、受信信号中の拡散符号と拡散符号の発生
器が発生した拡散符号との相関をとる相関器と、この相
関器から出力される相関値に応じて拡散符号の発生器で
発生させる拡散符号と受信信号中の拡散符号との同期を
とる同期制御回路と、同期された拡散符号によって受信
信号を逆拡散する逆拡散回路と、逆拡散された受信信号
を復調する復調回路とを備える復調装置において、相関
器に、拡散符号の発生器で発生させた拡散符号の１周期
を複数に分割する拡散符号の分割手段と、分割したそれ
ぞれの区間の部分相関値を算出する部分相関値算出手段
と、部分相関値の絶対値を求める絶対値演算手段と、各
分割区間の絶対値を拡散符号の１周期分加算して相関値
を算出する加算手段とを設け、同期制御回路が加算手段
からの相関値を観測することにより拡散符号の発生器で
発生させる拡散符号と受信信号中の拡散符号との同期を
とることにある。The features of the present invention to achieve the above object are described below as first to ninth inventions. A structural feature of the first invention is a demodulation device for receiving and demodulating a signal subjected to spectrum spreading, comprising: a generator of a spreading code for generating the same spreading code as a spreading code included in a received signal; A correlator for correlating a spread code in a signal with a spread code generated by a spread code generator, a spread code generated by a spread code generator according to a correlation value output from the correlator, and a received signal In a demodulation device comprising a synchronization control circuit for synchronizing with the spreading code in the inside, a despreading circuit for despreading the received signal by the synchronized spreading code, and a demodulation circuit for demodulating the despread received signal, A spread code dividing means for dividing one period of the spread code generated by the spread code generator into a plurality of parts, a partial correlation value calculating means for calculating a partial correlation value of each of the divided sections, Absolute value And an adder for calculating the correlation value by adding the absolute value of each divided section for one period of the spreading code, and the synchronization control circuit observes the correlation value from the adder. The object of the present invention is to synchronize a spread code generated by a spread code generator with a spread code in a received signal.

【００１６】第２の発明の構成上の特徴は、スペクトラ
ム拡散された信号を受信して復調する復調装置であっ
て、受信信号に含まれる拡散符号と同じ拡散符号を発生
する拡散符号の発生器と、受信信号中の拡散符号と拡散
符号の発生器が発生した拡散符号との相関をとる相関器
と、この相関器から出力される相関値に応じて拡散符号
の発生器で発生させる拡散符号と受信信号中の拡散符号
との同期をとる同期制御回路と、同期された拡散符号に
よって受信信号を逆拡散する逆拡散回路と、逆拡散され
た受信信号を復調する復調回路とを備える復調装置にお
いて、相関器に、拡散符号の発生器で発生させた拡散符
号の１周期を複数に分割する拡散符号の分割手段と、分
割したそれぞれの区間の部分相関値を算出する部分相関
値算出手段と、部分相関値の二乗値を求める二乗値演算
手段と、各分割区間の二乗値を拡散符号の１周期分加算
して相関値を算出する加算手段とを設け、同期制御回路
が加算手段からの相関値を観測することにより拡散符号
の発生器で発生させる拡散符号と受信信号中の拡散符号
との同期をとることにある。A structural feature of the second invention is a demodulation device for receiving and demodulating a signal subjected to spread spectrum, and a generator of a spread code for generating the same spread code as a spread code included in a received signal. And a correlator for correlating the spread code in the received signal with the spread code generated by the spread code generator, and a spread code generated by the spread code generator according to the correlation value output from the correlator. A demodulation device comprising: a synchronization control circuit for synchronizing the received signal with a spread code in the received signal; a despreading circuit for despreading the received signal by the synchronized spread code; and a demodulation circuit for demodulating the despread received signal. And a correlator comprising: a spreading code dividing means for dividing one period of the spreading code generated by the spreading code generator into a plurality of parts; and a partial correlation value calculating means for calculating a partial correlation value of each of the divided sections. ,part A square value calculating means for calculating a square value of the related value; and an adding means for calculating a correlation value by adding the square value of each divided section for one cycle of the spreading code, and the synchronization control circuit controls the correlation value from the adding means. Is observed to synchronize the spread code generated by the spread code generator with the spread code in the received signal.

【００１７】第３の発明の構成上の特徴は、第１または
第２の発明であって、相関器の前段にミキサが設けられ
ており、このミキサには受信信号の搬送波と同じ周波数
を発振可能な発振器からの信号を入力し、発振器の発振
周波数は、所定の周波数間隔で発振させた各周波数に対
応する同期制御回路の相関値の検出結果に応じて設定さ
れるものにおいて、同期制御回路が、拡散符号の分割手
段の分割数を所定値に設定する分割数設定手段と、発振
器で発振させる周波数の間隔を、分割手段が設けられて
いない場合の復調装置における発振器の発振周波数の間
隔に比べて大きくする周波数間隔設定手段とを備えるこ
とにある。A third aspect of the present invention is the first or second aspect of the present invention, wherein a mixer is provided at a stage preceding the correlator, and the mixer oscillates at the same frequency as the carrier of the received signal. A signal from a possible oscillator is input, and the oscillation frequency of the oscillator is set according to the detection result of the correlation value of the synchronization control circuit corresponding to each frequency oscillated at a predetermined frequency interval. However, the division number setting means for setting the division number of the spreading code division means to a predetermined value, and the interval of the frequency oscillated by the oscillator, the interval of the oscillation frequency of the oscillator in the demodulation device when the division means is not provided And a frequency interval setting means for increasing the frequency interval.

【００１８】第４の発明の構成上の特徴は、第３の発明
において、同期制御回路が、更に、相関値の検出結果が
所定レベル以上となる発振器の発振周波数の周波数範囲
を検出する第１の検出手段と、周波数範囲の検出後に拡
散符号の分割手段の分割数を所定値から減らすと共に検
出した周波数範囲内で発振器で発振させる周波数の間隔
を別の所定値以下とする設定値変更手段と、相関値の検
出結果が所定レベル以上の別のレベル以上となる発振器
の発振周波数の範囲を検出する第２の検出手段と、設定
値変更手段と第２の検出手段の動作を発振器の発振周波
数が確定するまで繰り返す発振周波数確定手段とを備え
ることにある。According to a fourth aspect of the present invention, in the third aspect, the synchronization control circuit further detects the frequency range of the oscillation frequency of the oscillator in which the correlation value detection result is equal to or higher than a predetermined level. Setting means for reducing the number of divisions of the spreading code dividing means after the detection of the frequency range from a predetermined value, and setting the interval of frequencies oscillated by the oscillator within the detected frequency range to another predetermined value or less. A second detecting means for detecting a range of the oscillation frequency of the oscillator in which the detection result of the correlation value is equal to or higher than another level equal to or higher than a predetermined level; and an operation of the setting value changing means and the second detecting means. And an oscillation frequency determining means that repeats until is determined.

【００１９】第５の発明の構成上の特徴は、第３の発明
において、同期制御回路が、更に、相関値の検出結果が
所定レベル以上となる発振器の発振周波数の周波数範囲
を検出する検出手段と、周波数範囲の検出後に拡散符号
の分割手段の分割動作を停止させる分割動作停止手段
と、発振させる周波数を検出した周波数範囲内で発振器
で搬送波の周波数の最小単位で変化させる発振周波数変
更手段と、相関値のピーク値で発振器の発振周波数を確
定する発振周波数確定手段とを備えることにある。According to a fifth aspect of the present invention, in the third aspect, the synchronization control circuit further comprises a detecting means for detecting a frequency range of an oscillation frequency of the oscillator in which a correlation value detection result is equal to or higher than a predetermined level. A dividing operation stopping unit for stopping the dividing operation of the spreading code dividing unit after the detection of the frequency range, and an oscillating frequency changing unit for changing the frequency to be oscillated by the oscillator in the minimum unit of the carrier frequency within the detected frequency range. Oscillation frequency determining means for determining the oscillation frequency of the oscillator based on the peak value of the correlation value.

【００２０】第６の発明の構成上の特徴は、第３の発明
において、同期制御回路が、更に、相関値の検出結果が
所定レベル以上となる発振器の発振周波数を１つ検出し
た後に、周波数間隔がこの発振周波数の前後の周波数に
おける相関値の検出結果を比較することによって相関値
の増減の傾向を検出する相関値の増減傾向検出手段と、
相関値が増大する方向の周波数に発振器の発振周波数を
シフトさせることによって相関値のピークを検出する相
関値ピークの検出手段と、ピーク検出後に拡散符号の分
割手段の分割数を減らすと共に発振器の発振周波数を搬
送波の周波数の最小単位で変化させる設定値変更手段
と、設定値変更後に検出した相関値のピーク値で発振器
の発振周波数を確定する発振周波数確定手段とを備える
ことにある。According to a sixth aspect of the present invention, in the third aspect, after the synchronization control circuit further detects one oscillation frequency of an oscillator whose correlation value detection result is equal to or higher than a predetermined level, A correlation value increase / decrease trend detecting means for detecting the increase / decrease tendency of the correlation value by comparing the correlation value detection results at frequencies before and after the oscillation frequency;
Correlation value peak detection means for detecting the correlation value peak by shifting the oscillation frequency of the oscillator to a frequency in the direction in which the correlation value increases, It is provided with a set value changing means for changing the frequency in the minimum unit of the frequency of the carrier wave, and an oscillation frequency determining means for determining the oscillation frequency of the oscillator with the peak value of the correlation value detected after the change of the set value.

【００２１】第７の発明の構成上の特徴は、第３の発明
において、同期制御回路が、更に、相関値の検出結果が
所定レベル以上となる発振器の発振周波数を１つ検出し
た後に、周波数間隔がこの発振周波数の前後の周波数に
おける相関値の検出結果を比較することによって相関値
の増減の傾向を検出する相関値の増減傾向検出手段と、
相関値が増大する方向の周波数に発振器の発振周波数を
シフトさせることによって相関値のピークを検出する相
関値ピークの検出手段と、ピーク検出後に拡散符号の分
割手段の動作を停止させると共に発振器の発振周波数を
搬送波の周波数の最小単位で変化させる設定値変更手段
と、設定値変更後に検出した相関値のピーク値で発振器
の発振周波数を確定する発振周波数確定手段とを備える
ことにある。According to a seventh aspect of the present invention, in the third aspect, after the synchronization control circuit further detects one oscillation frequency of an oscillator whose correlation value detection result is equal to or higher than a predetermined level, A correlation value increase / decrease trend detecting means for detecting the increase / decrease tendency of the correlation value by comparing the correlation value detection results at frequencies before and after the oscillation frequency;
The operation of the correlation value peak detecting means for detecting the peak of the correlation value by shifting the oscillation frequency of the oscillator to the frequency in the direction in which the correlation value increases, the operation of the spread code dividing means after the peak detection is stopped, and the oscillation of the oscillator is stopped. It is provided with a set value changing means for changing the frequency in the minimum unit of the frequency of the carrier wave, and an oscillation frequency determining means for determining the oscillation frequency of the oscillator with the peak value of the correlation value detected after the change of the set value.

【００２２】第８の発明の構成上の特徴は、第３の発明
において、同期制御回路が、更に、相関値の検出結果が
所定レベル以上となる発振器の発振周波数の周波数範囲
を検出する第１の検出手段と、周波数範囲の検出後にこ
の周波数範囲における相関値のピーク値を検出する相関
値ピーク検出手段と、拡散符号の分割手段の分割数を減
らすと共に、相関値のピーク値を検出した発振器の発振
周波数の前後の所定周波数範囲内で発振器が発振する周
波数の間隔を小さくする設定値変更手段と、設定値変更
後の相関値ピーク検出手段と設定値変更手段の動作を繰
り返して発振器の発振周波数を確定する発振周波数確定
手段とを備えることにある。According to an eighth aspect of the present invention, in the third aspect, the synchronization control circuit further detects the frequency range of the oscillation frequency of the oscillator in which the correlation value detection result is equal to or higher than a predetermined level. Detecting means, a correlation value peak detecting means for detecting a peak value of a correlation value in this frequency range after detecting the frequency range, and an oscillator which reduces the number of divisions of the spreading code dividing means and detects the peak value of the correlation value The setting value changing means for reducing the interval of the frequency at which the oscillator oscillates within a predetermined frequency range before and after the oscillation frequency of the oscillator, and the operation of the correlation value peak detecting means and the setting value changing means after the setting value change are repeated to oscillate the oscillator. An oscillation frequency determining means for determining a frequency is provided.

【００２３】第９の発明の構成上の特徴は、第３の発明
において、同期制御回路が、更に、相関値の検出結果が
所定レベル以上となる発振器の発振周波数の周波数範囲
を検出する第１の検出手段と、周波数範囲の検出後にこ
の周波数範囲における相関値のピーク値を検出する相関
値ピーク検出手段と、拡散符号の分割手段の分割動作を
停止させると共に、相関値のピーク値を検出した発振器
の発振周波数の前後の所定周波数範囲内で発振器が発振
する周波数の間隔を小さくする設定値変更手段と、設定
値変更後の相関値ピーク検出手段と設定値変更手段の動
作を繰り返して発振器の発振周波数を確定する発振周波
数確定手段とを備えることにある。According to a ninth aspect of the present invention, in the third aspect, the synchronization control circuit further detects the frequency range of the oscillation frequency of the oscillator in which the correlation value detection result is equal to or higher than a predetermined level. Detecting means, a correlation value peak detecting means for detecting the peak value of the correlation value in this frequency range after detecting the frequency range, and stopping the dividing operation of the spreading code dividing means, and detecting the peak value of the correlation value. The operation of the setting value changing means for reducing the interval of the frequency at which the oscillator oscillates within a predetermined frequency range before and after the oscillation frequency of the oscillator, the correlation value peak detecting means after the setting value change and the operation of the setting value changing means are repeated. An oscillation frequency determining means for determining an oscillation frequency is provided.

【００２４】第１０の発明の構成上の特徴は、第１から
第９の何れかの発明において、相関器が、拡散符号の発
生器が発生した拡散符号を所定の同一位相に保持したま
ま、拡散符号の複数の周期分の相関値を算出し、その平
均値を拡散符号の所定位相における相関値として検出す
ることにある。第１１の発明の構成上の特徴は、第１か
ら第１０の何れかの発明において、ミキサと相関器が並
列に２系統設けられており、ミキサの一方には発振器の
出力をそのまま入力し、他方には発振器の出力を９０°
移相して入力し、２つの相関器の出力を加算した値を相
関値として検出することにある。According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the correlator is configured to hold the spread code generated by the spread code generator at a predetermined same phase. It is to calculate a correlation value for a plurality of periods of the spreading code and detect an average value thereof as a correlation value at a predetermined phase of the spreading code. An eleventh aspect of the present invention is characterized in that, in any one of the first to tenth aspects, two systems of a mixer and a correlator are provided in parallel, and the output of the oscillator is directly input to one of the mixers, On the other hand, the output of the oscillator is 90 °
A phase shift is input, and a value obtained by adding outputs of two correlators is detected as a correlation value.

【００２５】以上の発明において、相関器としては、マ
ッチトフィルタやスライディング相関器を使用すること
ができる。第１から第１１の発明によれば、受信機側で
発生する搬送波周波数の許容範囲が広く、相関値ピーク
を短い時間で検出することができるスペクトラム拡散さ
れた信号の復調装置を提供することができる。In the above invention, a matched filter or a sliding correlator can be used as the correlator. According to the first to eleventh aspects, it is possible to provide a demodulator for a spread spectrum signal that has a wide allowable range of a carrier frequency generated on a receiver side and can detect a correlation value peak in a short time. it can.

【００２６】[0026]

【発明の実施の形態】以下添付図面を用いて本発明の実
施形態を具体的な実施例に基づいて詳細に説明する。図
３は直接スペクトラム拡散方式の受信機１０Ａにおけ
る、本発明のスペクトラム拡散された信号の復調装置３
０の第１の実施例の構成を示すブロック図であり、図１
で説明した従来の直接スペクトラム拡散方式の受信機１
０と同じ構成部材には同じ符号が付されている。Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 3 shows a demodulator 3 for a spread spectrum signal of the present invention in a receiver 10A of a direct spread spectrum system.
FIG. 1 is a block diagram showing the configuration of a first embodiment of FIG.
Of the conventional direct spread spectrum receiver 1 described in
The same components as those of 0 are denoted by the same reference numerals.

【００２７】従って、本発明の受信機１０Ａでもまず、
スペクトラム拡散された信号が受信アンテナ１１と無線
部１２とで受信されてミキサ１Ｂに入力される。ミキサ
１Ｂでは、受信信号と局部発振器である搬送波周波数発
生器２によって発振された搬送波と同一周波数の信号と
が混合され、受信信号中から搬送波が取り除かれる。ミ
キサ１Ｂで搬送波が除かれた受信信号は、符号同期回路
１３と逆拡散部（符号復調器）１４に入力される。Therefore, in the receiver 10A of the present invention, first,
The spread spectrum signal is received by the receiving antenna 11 and the radio unit 12, and is input to the mixer 1B. In mixer 1B, the received signal is mixed with a carrier having the same frequency as the carrier oscillated by carrier frequency generator 2 as a local oscillator, and the carrier is removed from the received signal. The received signal from which the carrier has been removed by the mixer 1B is input to a code synchronization circuit 13 and a despreading unit (code demodulator) 14.

【００２８】符号同期回路１３には受信信号に含まれる
拡散符号と同じ拡散符号を発生する拡散符号発生器４が
あり、発生した拡散符号と受信信号に含まれる拡散信号
の同期がとられる。図３には本発明における第１の実施
例の符号同期回路１３の構成が示されており、この構成
については後述する。符号同期回路１３において同期が
とれた拡散符号は符号同期回路１３から逆拡散部（符号
復調器）１４に入力される。逆拡散部１４では、拡散符
号発生器４からの拡散符号を受信信号に乗算することに
よって、受信信号から拡散符号を取り除く操作が行われ
る。このようにして受信信号から搬送波と拡散符号が取
り除かれて残った情報信号は、情報帯域バンドパスフィ
ルタ１５を通り、情報復調部１６で復調されて情報信号
となる。The code synchronization circuit 13 has a spread code generator 4 for generating the same spread code as the spread code included in the received signal, and synchronizes the generated spread code with the spread signal included in the received signal. FIG. 3 shows the configuration of the code synchronization circuit 13 according to the first embodiment of the present invention, and this configuration will be described later. The spread code synchronized in the code synchronization circuit 13 is input from the code synchronization circuit 13 to a despreading unit (code demodulator) 14. The despreading unit 14 performs an operation of removing the spread code from the received signal by multiplying the received signal by the spread code from the spread code generator 4. The information signal remaining after removing the carrier and the spreading code from the received signal passes through the information bandpass filter 15 and is demodulated by the information demodulation unit 16 to become an information signal.

【００２９】本発明の第１の実施例の符号同期回路１３
では、ミキサ１Ｂによって搬送波が取り除かれた受信信
号に含まれる拡散符号と符号同期回路１３内で発生させ
た拡散符号との相関値をとることによって、符号同期回
路１３内で発生させた拡散符号と受信信号中の拡散符号
との位相を合わせて同期をとること、および、搬送波周
波数発生器２において発生させる周波数を受信信号中の
搬送波の周波数に合わせることが行われる。そして、第
１の実施例では前述の相関値をとる回路を２系統用意
し、搬送波周波数発生器２で発生させた周波数の位相を
９０°ずらして受信信号に加えた後に、二乗器５Ａ，５
Ｂで二乗して加算しているが、これは搬送波の位相の影
響を無くすためである。この技術についてはスペクトラ
ム拡散通信方式において周知であるので、これ以上の説
明は省略する。The code synchronization circuit 13 according to the first embodiment of the present invention
Then, by taking the correlation value between the spread code included in the received signal from which the carrier wave has been removed by the mixer 1B and the spread code generated in the code synchronization circuit 13, the spread code generated in the code synchronization circuit 13 is obtained. Synchronization is performed by adjusting the phase with the spread code in the received signal, and the frequency generated by the carrier frequency generator 2 is adjusted to the frequency of the carrier in the received signal. In the first embodiment, two circuits for obtaining the above-described correlation value are prepared, and the phases of the frequencies generated by the carrier frequency generator 2 are shifted by 90 ° and added to the received signals, and then the squarers 5A and 5A are used.
This is done by squaring with B and adding, in order to eliminate the influence of the phase of the carrier wave. Since this technique is well known in the spread spectrum communication system, further description is omitted.

【００３０】従って、第１の実施例の符号同期回路１３
には、ミキサ１Ｂに並列にミキサ１Ａが設けられてお
り、搬送波周波数発生器２からの信号はミキサ１Ｂに入
力されると共に、９０°移相器９によって位相が９０°
ずらされてミキサ１Ａに入力されている。そして、ミキ
サ１Ａ，１Ｂにはそれぞれ受信信号中の拡散符号と拡散
符号発生器４で発生させた拡散符号との相関値をとる相
関器３Ａ，３Ｂが接続されており、相関器３Ａ，３Ｂで
それぞれ求められた相関値はこれに接続する二乗器５
Ａ，５Ｂにおいて二乗された後に加算器６で加算され
る。加算器６で加算された相関値には搬送波周波数の位
相成分が含まれていない。Therefore, the code synchronization circuit 13 of the first embodiment
Is provided with a mixer 1A in parallel with the mixer 1B, a signal from the carrier frequency generator 2 is input to the mixer 1B, and the phase is shifted by 90 ° by the 90 ° phase shifter 9.
The input is shifted to the mixer 1A. The mixers 1A and 1B are connected to correlators 3A and 3B, respectively, which take a correlation value between the spread code in the received signal and the spread code generated by the spread code generator 4. The respective calculated correlation values are connected to a squarer 5 connected thereto.
After being squared in A and 5B, they are added by the adder 6. The correlation value added by the adder 6 does not include the phase component of the carrier frequency.

【００３１】加算器６で求められた相関値は同期制御回
路７に入力される。この同期制御回路７には発振周波数
変更回路８Ａと発生符号の位相補正回路８Ｂが接続され
ている。発振周波数変更回路８Ａは搬送波周波数発生器
２における発振周波数を変更するものであり、発生符号
の位相補正回路８Ｂは拡散符号発生器４において発生さ
せられる拡散符号の位相を補正するものである。同期制
御回路７は、発振周波数変更回路８Ａから搬送波周波数
発生器２に指示される搬送波周波数を変更と、発生符号
の位相補正回路８Ｂから拡散符号発生器４に指示される
拡散符号の位相の補正を管理するものである。発振周波
数変更回路８Ａからの指示によって搬送波周波数発生器
２の発振周波数が搬送波の周波数に一致し、かつ、発生
符号の位相補正回路８Ｂの指示によって拡散符号発生器
４で発生した拡散符号の位相が受信信号中の拡散符号の
位相に一致すると、拡散符号発生器４からの拡散符号が
符号復調器１４に入力される。この状態では、ミキサ１
Ｂにおいて受信信号から搬送波が取り除かれ、符号復調
器１４において受信信号から拡散符号が取り除かれて、
受信信号中には変調あるいは符号化された情報信号のみ
が残る。この受信信号は情報帯域バンドパスフィルタ１
５を通り、情報復調部１６で復調されて情報信号とな
る。The correlation value obtained by the adder 6 is input to the synchronization control circuit 7. The synchronous control circuit 7 is connected to an oscillation frequency changing circuit 8A and a phase correction circuit 8B for generated codes. The oscillation frequency changing circuit 8A changes the oscillation frequency in the carrier frequency generator 2, and the generated code phase correction circuit 8B corrects the phase of the spread code generated in the spread code generator 4. The synchronization control circuit 7 changes the carrier frequency indicated by the oscillation frequency changing circuit 8A to the carrier frequency generator 2, and corrects the phase of the spread code indicated by the generated code phase correction circuit 8B to the spread code generator 4. Is to manage. The oscillation frequency of the carrier frequency generator 2 matches the carrier frequency according to the instruction from the oscillation frequency changing circuit 8A, and the phase of the spread code generated by the spread code generator 4 changes according to the instruction of the generated code phase correction circuit 8B. When the phase matches the phase of the spread code in the received signal, the spread code from the spread code generator 4 is input to the code demodulator 14. In this state, mixer 1
In B, the carrier is removed from the received signal, and the spread code is removed from the received signal in the code demodulator 14,
Only the modulated or encoded information signal remains in the received signal. This received signal is transmitted to the information bandpass filter 1
5 and is demodulated by the information demodulation unit 16 to become an information signal.

【００３２】従来の発振周波数変更回路８Ａの指示によ
る搬送波周波数発生器２の発振周波数の変更動作と、拡
散符号発生器４で発生させる拡散符号の位相補正回路８
Ｂの指示による位相の補正動作は、例えば、次のような
手順で行われていた。 (1) 発振周波数変更回路８Ａにより搬送波周波数発生器
２の発振周波数が決まる。The operation of changing the oscillating frequency of the carrier frequency generator 2 according to the instruction of the conventional oscillating frequency changing circuit 8A and the phase correction circuit 8 for the spreading code generated by the spreading code generator 4
The phase correcting operation according to the instruction of B is performed, for example, in the following procedure. (1) The oscillation frequency of the carrier frequency generator 2 is determined by the oscillation frequency changing circuit 8A.

【００３３】(2) この発振周波数で拡散符号発生器４が
発生した拡散符号と受信信号中の拡散符号とが１対１で
比較され、相関値が計算される。 (3) 発生符号の位相補正回路８Ｂにより拡散符号発生器
４の符号の位相が拡散符号１個分ずらされて(2) の動作
が行われる。 (4) 拡散符号発生器４の符号の位相をずらす動作が拡散
符号一周期分行われる。一例として、ＧＰＳのように拡
散符号として１０２３個で１周期のコードを使用してい
る場合は、例えば、１０２３回位相がずらされる。(2) The spread code generated by the spread code generator 4 at this oscillation frequency is compared with the spread code in the received signal on a one-to-one basis, and a correlation value is calculated. (3) The phase of the code of the spread code generator 4 is shifted by one spread code by the generated code phase correction circuit 8B, and the operation of (2) is performed. (4) The operation of shifting the phase of the code of the spread code generator 4 is performed for one cycle of the spread code. As an example, when a code having one cycle of 1023 is used as a spreading code like GPS, the phase is shifted, for example, 1023 times.

【００３４】(5) 拡散符号１周期分の相関値の最大値が
検出される。 (6) 相関値の最大値が所定のスレショルドと比較され
る。 (7) 相関値の最大値がスレショルド未満の場合は発振周
波数変更回路８Ａにより搬送波周波数発生器２の発振周
波数が０．００１ＭＨｚだけずらされる。 (8) (1) から(7) の動作がスレショルドを越えた相関値
の最大値のピーク値が検出されるまで続行される。(5) The maximum value of the correlation value for one period of the spreading code is detected. (6) The maximum value of the correlation value is compared with a predetermined threshold. (7) When the maximum value of the correlation value is less than the threshold, the oscillation frequency of the carrier frequency generator 2 is shifted by 0.001 MHz by the oscillation frequency changing circuit 8A. (8) The operations of (1) to (7) are continued until the peak value of the maximum correlation value exceeding the threshold is detected.

【００３５】図８は搬送波周波数発生器２の発振周波数
を０．００１ＭＨｚ毎に９．４７５ＭＨｚから９．４９
４ＭＨｚまで変化させた時の相関値の最大値の推移を示
すものである。この図から分かるように、スレショルド
レベルを８にしておけば、受信信号の搬送波周波数の周
波数が９．４８４ＭＨｚであることが検出できる。この
従来の方法によれば、搬送波周波数発生器２の発振周波
数を９．４７５ＭＨｚからスタートして０．００１ＭＨ
ｚ毎に増加させると、発振周波数が９．４８５ＭＨｚに
なった時点で搬送波周波数発生器２の発振周波数が検出
できることになる。しかしながら、この従来の方法で
は、搬送波周波数発生器２の発振周波数の変化分を送信
機側の搬送波周波数の単位まで細かくしなければならな
いので、搬送波周波数に合った発振周波数の検出までに
時間がかかっていた。FIG. 8 shows that the oscillation frequency of the carrier frequency generator 2 is increased from 9.475 MHz to 9.49 every 0.001 MHz.
The transition of the maximum value of the correlation value when the frequency is changed to 4 MHz is shown. As can be seen from this figure, if the threshold level is set to 8, it can be detected that the frequency of the carrier frequency of the received signal is 9.484 MHz. According to this conventional method, the oscillation frequency of the carrier wave frequency generator 2 is started from 9.475 MHz to 0.001 MHz.
When the frequency is increased for each z, the oscillation frequency of the carrier frequency generator 2 can be detected when the oscillation frequency becomes 9.485 MHz. However, in this conventional method, the change in the oscillation frequency of the carrier frequency generator 2 must be reduced to the unit of the carrier frequency on the transmitter side, so that it takes time to detect the oscillation frequency that matches the carrier frequency. I was

【００３６】そこで、本発明では、図３の相関器３Ａ，
３Ｂの中に、図４に示すように、拡散符号発生器４で発
生した拡散符号の１周期を複数に分割する拡散符号の分
割回路３３と、分割したそれぞれの区間の部分相関値を
求める部分相関値算出器３２と、部分相関値の絶対値を
求める絶対値演算回路３３と、各分割区間の絶対値を拡
散符号の１周期分加算する加算器３４とが設けられてい
る。加算器３４から出力された相関値は、図３で説明し
たように、二乗器５Ａ，５Ｂ、加算器６を経て同期制御
回路７に入力される。分割回路３３による拡散符号発生
器４で発生した拡散符号の１周期の分割数は、同期制御
回路７によって変更することができる。Therefore, in the present invention, the correlators 3A, 3A shown in FIG.
In FIG. 3B, as shown in FIG. 4, a spreading code dividing circuit 33 for dividing one period of the spreading code generated by the spreading code generator 4 into a plurality of parts, and a part for obtaining a partial correlation value of each divided section. A correlation value calculator 32, an absolute value calculation circuit 33 for calculating an absolute value of a partial correlation value, and an adder 34 for adding the absolute value of each divided section for one period of a spreading code are provided. The correlation value output from the adder 34 is input to the synchronization control circuit 7 via the squarers 5A and 5B and the adder 6, as described with reference to FIG. The number of divisions of the spreading code generated by the spreading code generator 4 in one cycle by the dividing circuit 33 can be changed by the synchronization control circuit 7.

【００３７】分割回路３３による拡散符号発生器４で発
生した拡散符号の１周期の分割数に応じた搬送波周波数
発生器２の発振周波数とその時の相関値の変化を、拡散
符号の１周期の分割数を１５、１０、５とした場合につ
いて図５から図７に示す。図５は拡散符号１周期を１５
に分割した時の発振周波数−相関値の特性を示し、図６
は拡散符号１周期を１０に分割した時の発振周波数−相
関値の特性を示す、図７は拡散符号１周期を５に分割し
た時の発振周波数−相関値の特性を示している。図５か
ら図７に示される特性を見ると、拡散符号１周期の分割
数が多いほど、相関値が所定レベル以上になる周波数の
幅が広くなることが分かる。このことから、受信機１０
Ａ側において、受信信号中の搬送波周波数を検出するた
めには、同期制御回路７によって最初は拡散符号１周期
の分割数を多くすると共に、受信機１０Ａ側の発振周波
数の間隔を粗くとることによって発振周波数−相関値の
特性の傾向を粗く検出し、即ち、発振周波数の粗い同期
をとり、その後に発振周波数の間隔を細かくして真の搬
送波周波数に発振周波数を合わせるようにすれば良い。The change of the oscillation frequency of the carrier frequency generator 2 and the correlation value at that time in accordance with the number of divisions of the spread code generated by the spread code generator 4 by the division circuit 33 in one cycle are divided by one cycle of the spread code. FIGS. 5 to 7 show the cases where the numbers are 15, 10, and 5. FIG. FIG. 5 shows that one cycle of the spreading code is 15
FIG. 6 shows the characteristic of the oscillation frequency-correlation value when divided into
7 shows the characteristics of the oscillation frequency-correlation value when one cycle of the spread code is divided into ten, and FIG. 7 shows the characteristics of the oscillation frequency-correlation value when one cycle of the spread code is divided into five. From the characteristics shown in FIGS. 5 to 7, it can be seen that the greater the number of divisions of one cycle of the spreading code, the wider the frequency range at which the correlation value becomes a predetermined level or more. From this, the receiver 10
On the A side, in order to detect the carrier frequency in the received signal, the synchronization control circuit 7 first increases the number of divisions of one cycle of the spread code and coarsens the interval between the oscillation frequencies of the receiver 10A. The characteristic of the oscillation frequency-correlation value may be roughly detected, that is, the oscillation frequency may be roughly synchronized, and then the interval between the oscillation frequencies may be narrowed to match the oscillation frequency with the true carrier frequency.

【００３８】このような同期制御回路７における発振周
波数の確定動作の具体的な実施例の１つを以下に説明す
る。まず、拡散符号の分割回路３３の分割数を図５に示
す１５のように大きくすると共に、搬送波周波数発生器
２の発振周波数の間隔を０．００５ＭＨｚのように大き
くする。この周波数間隔は図５にＡ〜Ｅの符号で示され
る。そして、相関値のスレショルドレベルを最初は１の
ように小さくする。すると、相関値のスレショルドレベ
ルが１以上の搬送波周波数発生器２の発振周波数の周波
数範囲が９．４７５ＭＨｚ〜９．４９５ＭＨｚであるこ
とが検出できる。One specific embodiment of the operation for determining the oscillation frequency in the synchronous control circuit 7 will be described below. First, the number of divisions of the spreading code dividing circuit 33 is increased as shown in FIG. 5 and the interval between the oscillation frequencies of the carrier frequency generator 2 is increased as 0.005 MHz. This frequency interval is indicated by reference numerals A to E in FIG. Then, the threshold level of the correlation value is reduced to 1 at first. Then, it can be detected that the frequency range of the oscillation frequency of the carrier frequency generator 2 having the correlation value threshold level of 1 or more is 9.475 MHz to 9.495 MHz.

【００３９】次に、拡散符号の分割回路３３の分割数を
図６に示す１０のように少し小さくすると共に、搬送波
周波数発生器２の発振周波数の間隔を０．００２ＭＨｚ
のように、０．００５ＭＨｚに比べて小さくする。する
と、相関値を検出する周波数を９．４７５ＭＨｚから
０．００２ＭＨｚ毎に９．４９５ＭＨｚまでとした発振
周波数−相関値の特性は図６に示すようになる。そし
て、相関値のスレショルドレベルを４のように少し大き
くすると、相関値のスレショルドレベルが４以上の搬送
波周波数発生器２の発振周波数の周波数範囲が９．４７
９ＭＨｚ〜９．４８９ＭＨｚのように狭まって検出でき
る。Next, the number of divisions of the spreading code dividing circuit 33 is slightly reduced as shown in FIG. 6 by 10 and the interval between the oscillation frequencies of the carrier frequency generator 2 is set to 0.002 MHz.
As in the case of 0.005 MHz. Then, the characteristic of the oscillation frequency-correlation value in which the frequency for detecting the correlation value is set from 9.475 MHz to 9.495 MHz every 0.002 MHz becomes as shown in FIG. When the threshold value of the correlation value is slightly increased, such as 4, the frequency range of the oscillation frequency of the carrier frequency generator 2 having the threshold value of the correlation value of 4 or more is 9.47.
It can be detected as narrow as 9 MHz to 9.489 MHz.

【００４０】更に、拡散符号の分割回路３３の分割数を
図７に示す５のように更に小さくする。また、搬送波周
波数発生器２の発振周波数の間隔は０．００２ＭＨｚの
ままとする。すると、相関値を検出する周波数を９．４
７９ＭＨｚから０．００２ＭＨｚ毎に９．４８９ＭＨｚ
までとした発振周波数−相関値の特性は図７に示すよう
になる。そして、相関値のスレショルドレベルを６のよ
うに更に大きくする。この結果、相関値のスレショルド
レベルが６以上の搬送波周波数発生器２の発振周波数の
周波数範囲が９．４８１ＭＨｚ〜９．４８６ＭＨｚのよ
うに更に狭まって検出できる。Further, the number of divisions of the spreading code dividing circuit 33 is further reduced as shown in FIG. The interval between the oscillation frequencies of the carrier frequency generator 2 remains at 0.002 MHz. Then, the frequency for detecting the correlation value is set to 9.4.
9.489 MHz from 79 MHz every 0.002 MHz
The characteristics of the oscillation frequency-correlation value up to this point are as shown in FIG. Then, the threshold level of the correlation value is further increased as shown in FIG. As a result, the frequency range of the oscillating frequency of the carrier frequency generator 2 having a threshold value of the correlation value of 6 or more can be detected as narrowing as 9.481 MHz to 9.486 MHz.

【００４１】最後に、拡散符号の分割回路３３の分割数
を図８に示すように０とし、搬送波周波数発生器２の発
振周波数の間隔を０．００１ＭＨｚにする。すると、相
関値を検出する周波数を９．４８１ＭＨｚから０．００
１ＭＨｚ毎に９．４８６ＭＨｚまでとした発振周波数−
相関値の特性は図８に示すようになる。そして、相関値
のスレショルドレベルを８のように更に大きくする。こ
の結果、相関値のスレショルドレベルが８以上の搬送波
周波数発生器２の発振周波数の周波数は９．４８４ＭＨ
ｚに確定することができる。Finally, the number of divisions of the spreading code dividing circuit 33 is set to 0 as shown in FIG. 8, and the interval between the oscillation frequencies of the carrier frequency generator 2 is set to 0.001 MHz. Then, the frequency for detecting the correlation value is changed from 9.481 MHz to 0.00.
Oscillation frequency up to 9.486 MHz per 1 MHz-
The characteristics of the correlation value are as shown in FIG. Then, the threshold level of the correlation value is further increased as shown in FIG. As a result, the oscillation frequency of the carrier frequency generator 2 having a correlation value threshold level of 8 or more is 9.484 MHz.
z.

【００４２】なお、以上のような搬送波周波数に等しい
搬送波周波数発生器２の発振周波数の周波数の確定方法
において、以下のような実施例も可能である。 (1) 拡散符号の分割回路３３の分割数を最初大きくし、
相関値の検出結果が所定レベル以上となる搬送波周波数
発生器２の発振周波数の周波数範囲を検出した後に、拡
散符号の分割回路３３の分割動作を停止させると共に、
検出した周波数範囲で搬送波周波数発生器２の発振周波
数を細かく変化させる（周波数間隔を小さくする）こと
により、搬送波周波数発生器２の発振周波数を確定す
る。In the above method for determining the frequency of the oscillation frequency of the carrier frequency generator 2 equal to the carrier frequency, the following embodiment is also possible. (1) First, increase the number of divisions of the spreading code dividing circuit 33,
After detecting the frequency range of the oscillation frequency of the carrier frequency generator 2 in which the detection result of the correlation value is equal to or higher than a predetermined level, the dividing operation of the spreading code dividing circuit 33 is stopped,
The oscillation frequency of the carrier frequency generator 2 is determined by finely changing the oscillation frequency of the carrier frequency generator 2 (decreasing the frequency interval) within the detected frequency range.

【００４３】(2) 拡散符号の分割回路３３の分割数を最
初大きくし、相関値の検出結果が所定レベル以上となる
搬送波周波数発生器２の発振周波数を１つ検出した後
に、周波数間隔がこの発振周波数の前後の周波数におい
て相関値の検出結果を比較し、相関値の検出結果の大き
い方の周波数に搬送波周波数発生器２の発振周波数をシ
フトさせることによって相関値のピークを検出し、ピー
ク検出後は拡散符号の分割回路３３の分割数を減らすと
共に、搬送波周波数発生器２の発振周波数の周波数間隔
を小さくすることによって、搬送波周波数発生器２の発
振周波数を確定する。(2) The number of divisions of the spreading code division circuit 33 is first increased, and after detecting one oscillation frequency of the carrier frequency generator 2 at which the correlation value detection result is equal to or higher than a predetermined level, the frequency interval is set to this value. The detection result of the correlation value is compared at frequencies before and after the oscillation frequency, and the peak of the correlation value is detected by shifting the oscillation frequency of the carrier frequency generator 2 to the frequency with the larger detection result of the correlation value. Thereafter, the oscillation frequency of the carrier frequency generator 2 is determined by reducing the number of divisions of the spreading code division circuit 33 and reducing the frequency interval of the oscillation frequency of the carrier frequency generator 2.

【００４４】(3) 拡散符号の分割回路３３の分割数を最
初大きくし、相関値の検出結果が所定レベル以上となる
搬送波周波数発生器２の発振周波数を１つ検出した後
に、周波数間隔がこの発振周波数の前後の周波数と減算
した周波数において相関値の検出結果を比較し、相関値
の検出結果の大きい方の周波数に搬送波周波数発生器２
の発振周波数をシフトさせることによって相関値のピー
クを検出し、ピーク検出後は拡散符号の分割回路３３の
動作を停止させると共に、搬送波周波数発生器２の発振
周波数の周波数間隔を小さくすることによって、搬送波
周波数発生器２の発振周波数を確定する。(3) The number of divisions of the spreading code dividing circuit 33 is first increased, and after detecting one oscillation frequency of the carrier frequency generator 2 at which the correlation value detection result is equal to or higher than a predetermined level, the frequency interval is set to this value. The detection result of the correlation value is compared between the frequency before and after the oscillation frequency and the subtracted frequency, and the carrier frequency generator 2 is set to the frequency having the larger detection result of the correlation value.
The peak of the correlation value is detected by shifting the oscillating frequency of, and after the peak is detected, the operation of the spread code dividing circuit 33 is stopped, and the frequency interval of the oscillating frequency of the carrier frequency generator 2 is reduced. The oscillation frequency of the carrier frequency generator 2 is determined.

【００４５】(4) 拡散符号の分割回路３３の分割数を最
初大きくし、相関値の検出結果が所定レベル以上となる
搬送波周波数発生器２の発振周波数の周波数範囲を検出
した後に、この周波数範囲における相関値のピーク値を
検出し、拡散符号の分割回路３３の分割数を減らすと共
に、相関値のピーク値を検出した搬送波周波数発生器２
の発振周波数の前後の所定周波数範囲内で搬送波周波数
発生器２の発振周波数の周波数間隔を小さくし、この周
波数範囲における相関値のピーク値を検出する動作を、
搬送波周波数発生器２の発振周波数が確定するまで繰り
返す。(4) The number of divisions of the spreading code dividing circuit 33 is first increased, and after detecting the frequency range of the oscillating frequency of the carrier frequency generator 2 in which the correlation value detection result is equal to or higher than a predetermined level, , The number of divisions of the spreading code dividing circuit 33 is reduced, and the carrier frequency generator 2 that detects the peak value of the correlation value is detected.
The operation of reducing the frequency interval of the oscillation frequency of the carrier wave frequency generator 2 within a predetermined frequency range before and after the oscillation frequency of, and detecting the peak value of the correlation value in this frequency range,
This is repeated until the oscillation frequency of the carrier frequency generator 2 is determined.

【００４６】(5) 拡散符号の分割回路３３の分割数を最
初大きくし、相関値の検出結果が所定レベル以上となる
搬送波周波数発生器２の発振周波数の周波数範囲を検出
した後に、この周波数範囲における相関値のピーク値を
検出し、拡散符号の分割回路３３の分割動作を停止させ
ると共に、相関値のピーク値を検出した搬送波周波数発
生器２の発振周波数の前後の所定周波数範囲内で搬送波
周波数発生器２の発振周波数の周波数間隔を小さくし、
この周波数範囲における相関値のピーク値を検出する動
作を搬送波周波数発生器２の発振周波数が確定するまで
繰り返す。(5) The number of divisions of the spreading code dividing circuit 33 is first increased, and after detecting the frequency range of the oscillating frequency of the carrier frequency generator 2 in which the correlation value detection result is equal to or higher than a predetermined level, , The dividing operation of the spread code dividing circuit 33 is stopped, and the carrier frequency falls within a predetermined frequency range before and after the oscillation frequency of the carrier frequency generator 2 that detects the peak value of the correlation value. The frequency interval of the oscillation frequency of the generator 2 is reduced,
The operation of detecting the peak value of the correlation value in this frequency range is repeated until the oscillation frequency of the carrier frequency generator 2 is determined.

【００４７】なお、以上の実施例において、相関器が拡
散符号の発生器が発生した拡散符号を所定の同一位相に
保持したまま、拡散符号の複数の周期分の相関値を算出
し、その平均値を拡散符号の所定位相における相関値と
して検出するようにしても良い。また、相関器にはマッ
チトフィルタ、或いは、スライディング相関器を使用す
ることができる。In the above embodiment, the correlator calculates the correlation value for a plurality of periods of the spread code while maintaining the spread code generated by the spread code generator at a predetermined same phase, and calculates the average value. The value may be detected as a correlation value at a predetermined phase of the spreading code. Further, a matched filter or a sliding correlator can be used as the correlator.

【００４８】図９は直接スペクトラム拡散方式の受信機
１０Ｂにおける、本発明のスペクトラム拡散された信号
の第２の実施例の復調装置３０Ａの構成を示すブロック
図であり、図１で説明した従来の直接スペクトラム拡散
方式の受信機１０と同じ構成部材には同じ符号が付され
ている。また、第２の実施例の復調装置３０Ａが第１の
実施例の復調装置３０と異なる点は、符号同期回路１３
における相関器３Ｃ，３Ｄの構成、および、相関器３
Ｃ，３Ｄと加算器６との間に二乗器が設けられていない
点のみである。従って、第２の実施例の符号同期回路１
３の内部の構成で、第１の実施例の符号同期回路１３の
内部の構成と同じものには同じ符号を付してその説明を
省略する。FIG. 9 is a block diagram showing the configuration of a demodulator 30A according to a second embodiment of the spread spectrum signal of the present invention in a receiver 10B of the direct spread spectrum system. The same components as those of the direct spread spectrum receiver 10 are denoted by the same reference numerals. The difference between the demodulation device 30A of the second embodiment and the demodulation device 30 of the first embodiment is that
Configuration of the correlators 3C and 3D, and the correlator 3
The only difference is that no squarer is provided between C and 3D and the adder 6. Therefore, the code synchronization circuit 1 of the second embodiment
3, the same components as those in the code synchronization circuit 13 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

【００４９】第２の実施例における相関器３Ｃ，３Ｄの
中には、図１０に示すように、拡散符号発生器４で発生
した拡散符号の１周期を複数に分割する拡散符号の分割
回路３３と、分割したそれぞれの区間の部分相関値を求
める部分相関値算出器３２と、部分相関値の二乗値を求
める二乗回路３５と、各分割区間の絶対値を拡散符号の
１周期分加算する加算器３４とが設けられている。そし
て、相関器３Ｃ，３Ｄ内に二乗回路３５が設けられてい
るので、相関器３Ｃ，３Ｄと加算器６との間には、第１
の実施例に設けられていた二乗器５Ａ，５Ｂが省略され
ている。加算器３４から出力された相関値は、図９に示
される加算器６を経て同期制御回路７に入力される。分
割回路３３による拡散符号発生器４で発生した拡散符号
の１周期の分割数は、同期制御回路７によって変更する
ことができる。In the correlators 3C and 3D of the second embodiment, as shown in FIG. 10, a spreading code dividing circuit 33 for dividing one cycle of the spreading code generated by the spreading code generator 4 into a plurality of periods. And a partial correlation value calculator 32 for calculating a partial correlation value of each of the divided sections, a squaring circuit 35 for calculating a square value of the partial correlation value, and an addition for adding the absolute value of each of the divided sections for one period of the spreading code. Device 34 is provided. Since the squaring circuit 35 is provided in the correlators 3C and 3D, the first circuit is provided between the correlators 3C and 3D and the adder 6.
The squarers 5A and 5B provided in the embodiment of FIG. The correlation value output from the adder 34 is input to the synchronization control circuit 7 via the adder 6 shown in FIG. The number of divisions of the spreading code generated by the spreading code generator 4 in one cycle by the dividing circuit 33 can be changed by the synchronization control circuit 7.

【００５０】第２の実施例の分割回路３３による拡散符
号発生器４で発生した拡散符号の１周期の分割数に応じ
た搬送波周波数発生器２の発振周波数とその時の相関値
の変化は、第１の実施例と同じであり、拡散符号の１周
期の分割数を１５、１０、５とした場合の発振周波数−
相関値の特性は図５から図７と全く同じである。従っ
て、第２の実施例の復調装置３０Ａの搬送波周波数の検
出動作は、第１の実施例の復調装置３０と全く同じであ
る。この結果、第２の実施例の復調装置３０Ａによって
も、第１の実施例の復調装置３０と同様の手順で搬送波
周波数と同じ周波数を短時間で検出することができる。The change of the oscillation frequency of the carrier frequency generator 2 and the correlation value at that time according to the number of divisions of one cycle of the spreading code generated by the spreading code generator 4 by the splitting circuit 33 of the second embodiment is described by Oscillation frequency when the number of divisions of one cycle of the spreading code is set to 15, 10 and 5,
The characteristics of the correlation value are exactly the same as in FIGS. Therefore, the operation of detecting the carrier frequency of the demodulation device 30A of the second embodiment is exactly the same as that of the demodulation device 30 of the first embodiment. As a result, the demodulator 30A of the second embodiment can detect the same frequency as the carrier frequency in a short time in the same procedure as the demodulator 30 of the first embodiment.

【００５１】なお、以上の実施例では、直接拡散方式の
受信装置の構成を説明したが、本発明のスペクトラム拡
散された信号の復調装置は直接拡散方式に限定されるも
のではなく、周波数ホッピング方式の受信装置にも本発
明を有効に適用することができる。In the above embodiments, the configuration of the direct spread type receiving apparatus has been described. However, the demodulation apparatus for the spread spectrum signal of the present invention is not limited to the direct spread type, but may be a frequency hopping type. The present invention can be effectively applied to the receiving device of (1).

【００５２】[0052]

【発明の効果】以上説明したように、本発明のスペクト
ラム拡散された信号の復調装置によれば、受信機側で発
生する搬送波周波数の許容範囲が広く、相関値ピークを
短い時間で精度良く検出することができるスペクトラム
拡散された信号の復調装置を提供することができるとい
う効果がある。また、拡散符号の複数の周期分の相関値
を算出し、その平均値を拡散符号の所定位相の相関値と
して検出すれば、雑音に対する耐性が向上する。As described above, according to the demodulator for spread spectrum signals of the present invention, the allowable range of the carrier frequency generated on the receiver side is wide, and the correlation value peak can be accurately detected in a short time. There is an effect that it is possible to provide a demodulation device for a spread spectrum signal that can be used. Further, if a correlation value for a plurality of cycles of the spread code is calculated and an average value thereof is detected as a correlation value of a predetermined phase of the spread code, resistance to noise is improved.

【図面の簡単な説明】[Brief description of the drawings]

【図１】従来の直接スペクトル拡散方式の送受信機の構
成を示すブロック図である。FIG. 1 is a block diagram showing a configuration of a conventional direct spread spectrum transceiver.

【図２】従来の相関値の検出方法を説明する図である。FIG. 2 is a diagram illustrating a conventional correlation value detection method.

【図３】本発明のスペクトラム拡散された信号の復調装
置の第１の実施例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 first embodiment of a demodulator for a spread spectrum signal of the present invention.

【図４】本発明の第１の実施例における相関値の検出方
法を説明する図である。FIG. 4 is a diagram illustrating a method for detecting a correlation value according to the first embodiment of the present invention.

【図５】拡散符号１周期を１５に分割した時の発振周波
数−相関値の特性図である。FIG. 5 is a characteristic diagram of an oscillation frequency-correlation value when one cycle of a spreading code is divided into 15;

【図６】拡散符号１周期を１０に分割した時の発振周波
数−相関値の特性図である。FIG. 6 is a characteristic diagram of an oscillation frequency-correlation value when one cycle of a spread code is divided into ten.

【図７】拡散符号１周期を５に分割した時の発振周波数
−相関値の特性図である。FIG. 7 is a characteristic diagram of an oscillation frequency-correlation value when one period of a spread code is divided into five.

【図８】拡散符号１周期を分割しない時の発振周波数−
相関値の特性図である。FIG. 8 shows an oscillation frequency when one period of the spreading code is not divided.
It is a characteristic diagram of a correlation value.

【図９】本発明のスペクトラム拡散された信号の復調装
置の第２の実施例の構成を示すブロック図である。FIG. 9 is a block diagram showing the configuration of a second embodiment of the demodulator for spread spectrum signals of the present invention.

【図１０】本発明の第２の実施例における相関値の検出
方法を説明する図である。FIG. 10 is a diagram illustrating a method for detecting a correlation value according to a second embodiment of the present invention.

【符号の説明】[Explanation of symbols]

１Ａ，１Ｂ…ミキサ ２…搬送波周波数発生器 ３Ａ，３Ｂ…第１の実施例の相関器 ３Ｃ，３Ｄ…第２の実施例の相関器 ４…拡散符号発生器 ５Ａ，５Ｂ…二乗器 ６…加算器 ７…同期制御回路 ８Ａ…発振周波数変更回路 ８Ｂ…発生符号の位相補正回路 ９…９０°移相器 １０，１０Ａ，１０Ｂ…受信機 １３…符号同期回路 １４…逆拡散部（符号復調器） １７…第１のシフトレジスタ １８…第２のシフトレジスタ ３０…第１の実施例の復調装置 ３０Ａ…第２の実施例の復調装置 ３１…分割回路 ３２…部分相関値算出器 ３３…絶対値演算回路 ３４…加算器 ３５…二乗器 1A, 1B: Mixer 2: Carrier frequency generator 3A, 3B: Correlator of the first embodiment 3C, 3D: Correlator of the second embodiment 4: Spread code generator 5A, 5B: Squarer 6: Addition 7 ... Synchronization control circuit 8A ... Oscillation frequency change circuit 8B ... Phase correction circuit for generated code 9 ... 90 ° phase shifter 10, 10A, 10B ... Receiver 13 ... Code synchronization circuit 14 ... Despreading unit (code demodulator) Reference Signs List 17 first shift register 18 second shift register 30 demodulator of first embodiment 30A demodulator of second embodiment 31 dividing circuit 32 partial correlation value calculator 33 absolute value calculation Circuit 34: Adder 35: Squarer

Claims (13)

【特許請求の範囲】[Claims] 【請求項１】 スペクトラム拡散された信号を受信して
復調する復調装置であって、受信信号に含まれる拡散符
号と同じ拡散符号を発生する拡散符号の発生器と、受信
信号中の拡散符号と前記拡散符号の発生器が発生した拡
散符号との相関をとる相関器と、この相関器から出力さ
れる相関値に応じて前記拡散符号の発生器で発生させる
拡散符号と前記受信信号中の拡散符号との同期をとる同
期制御回路と、同期された拡散符号によって受信信号を
逆拡散する逆拡散回路と、逆拡散された受信信号を復調
する復調回路とを備える復調装置において、 前記相関器に、前記拡散符号の発生器で発生させた拡散
符号の１周期を複数に分割する拡散符号の分割手段と、
分割したそれぞれの区間の部分相関値を算出する部分相
関値算出手段と、前記部分相関値の絶対値を求める絶対
値演算手段と、各分割区間の前記絶対値を前記拡散符号
の１周期分加算して相関値を算出する加算手段とを設
け、 前記同期制御回路が前記加算手段からの相関値を観測す
ることにより前記拡散符号の発生器で発生させる拡散符
号と前記受信信号中の拡散符号との同期をとることを特
徴とするスペクトラム拡散された信号の復調装置。1. A demodulator for receiving and demodulating a spread spectrum signal, comprising: a generator of a spread code for generating the same spread code as a spread code included in a received signal; A correlator for correlating with the spreading code generated by the spreading code generator; a spreading code generated by the spreading code generator in accordance with a correlation value output from the correlator; and a spreading code in the received signal. A synchronization control circuit that synchronizes with the code, a despreading circuit that despreads the received signal by the synchronized spreading code, and a demodulation device that includes a demodulation circuit that demodulates the despread received signal. Spreading code dividing means for dividing one cycle of the spreading code generated by the spreading code generator into a plurality,
A partial correlation value calculating means for calculating a partial correlation value of each divided section; an absolute value calculating means for calculating an absolute value of the partial correlation value; and adding the absolute value of each divided section for one cycle of the spreading code And an adder for calculating a correlation value, and the spread code generated by the generator of the spread code and the spread code in the received signal by the synchronization control circuit observing the correlation value from the adder. A demodulator for a spread-spectrum signal, characterized in that: 【請求項２】 スペクトラム拡散された信号を受信して
復調する復調装置であって、受信信号に含まれる拡散符
号と同じ拡散符号を発生する拡散符号の発生器と、受信
信号中の拡散符号と前記拡散符号の発生器が発生した拡
散符号との相関をとる相関器と、この相関器から出力さ
れる相関値に応じて前記拡散符号の発生器で発生させる
拡散符号と前記受信信号中の拡散符号との同期をとる同
期制御回路と、同期された拡散符号によって受信信号を
逆拡散する逆拡散回路と、逆拡散された受信信号を復調
する復調回路とを備える復調装置において、 前記相関器に、前記拡散符号の発生器で発生させた拡散
符号の１周期を複数に分割する拡散符号の分割手段と、
分割したそれぞれの区間の部分相関値を算出する部分相
関値算出手段と、前記部分相関値の二乗値を求める二乗
値演算手段と、各分割区間の前記二乗値を前記拡散符号
の１周期分加算して相関値を算出する加算手段とを設
け、 前記同期制御回路が前記加算手段からの相関値を観測す
ることにより前記拡散符号の発生器で発生させる拡散符
号と前記受信信号中の拡散符号との同期をとることを特
徴とするスペクトラム拡散された信号の復調装置。2. A demodulator for receiving and demodulating a spread spectrum signal, comprising: a generator of a spreading code for generating the same spreading code as a spreading code included in the received signal; A correlator for correlating with the spreading code generated by the spreading code generator; a spreading code generated by the spreading code generator in accordance with a correlation value output from the correlator; and a spreading code in the received signal. A synchronization control circuit that synchronizes with the code, a despreading circuit that despreads the received signal by the synchronized spreading code, and a demodulation device that includes a demodulation circuit that demodulates the despread received signal. Spreading code dividing means for dividing one cycle of the spreading code generated by the spreading code generator into a plurality,
A partial correlation value calculating means for calculating a partial correlation value of each divided section; a square value calculating means for calculating a square value of the partial correlation value; and adding the square value of each divided section for one cycle of the spreading code And an adder for calculating a correlation value, and the spread code generated by the generator of the spread code and the spread code in the received signal by the synchronization control circuit observing the correlation value from the adder. A demodulator for a spread-spectrum signal, characterized in that: 【請求項３】 請求項１または２に記載のスペクトラム
拡散された信号の復調装置であって、前記相関器の前段
にミキサが設けられており、このミキサには受信信号の
搬送波と同じ周波数を発振可能な発振器からの信号を入
力し、前記発振器の発振周波数は、所定の周波数間隔で
発振させた各周波数に対応する前記同期制御回路の前記
相関値の検出結果に応じて設定されるものにおいて、 前記同期制御回路が、前記拡散符号の分割手段の分割数
を所定値に設定する分割数設定手段と、前記発振器で発
振させる周波数の間隔を、前記分割手段が設けられてい
ない場合の復調装置における発振器の発振周波数の間隔
に比べて大きくする周波数間隔設定手段とを備えること
を特徴とするスペクトラム拡散された信号の復調装置。3. The demodulator for a spread spectrum signal according to claim 1, wherein a mixer is provided at a stage preceding the correlator, and the mixer has the same frequency as the carrier of the received signal. A signal from an oscillating oscillator is input, and the oscillation frequency of the oscillator is set according to the result of detection of the correlation value of the synchronization control circuit corresponding to each frequency oscillated at a predetermined frequency interval. A synchronization control circuit for setting a division number of the spreading code division means to a predetermined value; a division number setting means for setting an interval between frequencies oscillated by the oscillator; and a demodulation device when the division means is not provided. And a frequency interval setting means for setting the interval to be larger than the interval between the oscillation frequencies of the oscillators. 【請求項４】 請求項３に記載のスペクトラム拡散され
た信号の復調装置において、 前記同期制御回路が、更に、前記相関値の検出結果が所
定レベル以上となる前記発振器の発振周波数の周波数範
囲を検出する第１の検出手段と、前記周波数範囲の検出
後に前記拡散符号の分割手段の分割数を前記所定値から
減らすと共に検出した前記周波数範囲内で前記発振器で
発振させる周波数の間隔を前記別の所定値以下とする設
定値変更手段と、前記相関値の検出結果が前記所定レベ
ル以上の別のレベル以上となる前記発振器の発振周波数
の範囲を検出する第２の検出手段と、前記設定値変更手
段と前記第２の検出手段の動作を前記発振器の発振周波
数が確定するまで繰り返す発振周波数確定手段とを備え
ることを特徴とするスペクトラム拡散された信号の復調
装置。4. The demodulation device for a spread spectrum signal according to claim 3, wherein the synchronization control circuit further sets a frequency range of an oscillation frequency of the oscillator in which a detection result of the correlation value is equal to or higher than a predetermined level. First detecting means for detecting, and after the frequency range is detected, the number of divisions of the spreading code dividing means is reduced from the predetermined value, and the interval of the frequency oscillated by the oscillator within the detected frequency range is set to another one. Setting value changing means for setting the correlation value to be equal to or less than a predetermined value; second detecting means for detecting a range of the oscillation frequency of the oscillator in which the detection result of the correlation value is equal to or higher than another level equal to or higher than the predetermined level; Means for repeating the operation of the second detection means until the oscillation frequency of the oscillator is determined. No. demodulator. 【請求項５】 請求項３に記載のスペクトラム拡散され
た信号の復調装置において、 前記同期制御回路が、更に、前記相関値の検出結果が所
定レベル以上となる前記発振器の発振周波数の周波数範
囲を検出する検出手段と、前記周波数範囲の検出後に前
記拡散符号の分割手段の分割動作を停止させる分割動作
停止手段と、前記発振器で発振させる周波数を検出した
前記周波数範囲内で搬送波の周波数の最小単位で変化さ
せる発振周波数変更手段と、前記相関値のピーク値で前
記発振器の発振周波数を確定する発振周波数確定手段と
を備えることを特徴とするスペクトラム拡散された信号
の復調装置。5. The demodulator for a spread spectrum signal according to claim 3, wherein the synchronization control circuit further controls a frequency range of an oscillation frequency of the oscillator in which a detection result of the correlation value is equal to or higher than a predetermined level. Detecting means for detecting, dividing operation stopping means for stopping the dividing operation of the spreading code dividing means after detecting the frequency range, and a minimum unit of the frequency of the carrier wave in the frequency range in which the frequency oscillated by the oscillator is detected. And an oscillation frequency determining means for determining the oscillation frequency of the oscillator based on the peak value of the correlation value. 【請求項６】 請求項３に記載のスペクトラム拡散され
た信号の復調装置において、 前記同期制御回路が、更に、前記相関値の検出結果が所
定レベル以上となる前記発振器の発振周波数を１つ検出
した後に、周波数間隔がこの発振周波数の前後の周波数
における前記相関値の検出結果を比較することによって
前記相関値の増減の傾向を検出する相関値の増減傾向検
出手段と、相関値が増大する方向の周波数に前記発振器
の発振周波数をシフトさせることによって前記相関値の
ピークを検出する相関値ピークの検出手段と、ピーク検
出後に前記拡散符号の分割手段の分割数を減らすと共に
前記発振器の発振周波数を搬送波の周波数の最小単位で
変化させる設定値変更手段と、設定値変更後に検出した
前記相関値のピーク値で前記発振器の発振周波数を確定
する発振周波数確定手段とを備えることを特徴とするス
ペクトラム拡散された信号の復調装置。6. The demodulator according to claim 3, wherein the synchronization control circuit further detects one oscillation frequency of the oscillator at which the detection result of the correlation value is equal to or higher than a predetermined level. After that, a correlation value increasing / decreasing trend detecting means for detecting the increasing / decreasing tendency of the correlation value by comparing the correlation value detection results at frequencies before and after the oscillation frequency, and a direction in which the correlation value increases A correlation value peak detecting means for detecting a peak of the correlation value by shifting the oscillation frequency of the oscillator to a frequency of the oscillator, and reducing the number of divisions of the spreading code dividing means after the peak detection, and reducing the oscillation frequency of the oscillator. Setting value changing means for changing the frequency of the carrier in the minimum unit; Spread spectrum signal demodulation device characterized by comprising an oscillation frequency determining means for determining the number. 【請求項７】 請求項３に記載のスペクトラム拡散され
た信号の復調装置において、 前記同期制御回路が、更に、前記相関値の検出結果が所
定レベル以上となる前記発振器の発振周波数を１つ検出
した後に、周波数間隔がこの発振周波数の前後の周波数
における前記相関値の検出結果を比較することによって
前記相関値の増減の傾向を検出する相関値の増減傾向検
出手段と、相関値が増大する方向の周波数に前記発振器
の発振周波数をシフトさせることによって前記相関値の
ピークを検出する相関値ピークの検出手段と、ピーク検
出後に前記拡散符号の分割手段の動作を停止させると共
に前記発振器の発振周波数を搬送波の周波数の最小単位
で変化させる設定値変更手段と、設定値変更後に検出し
た前記相関値のピーク値で前記発振器の発振周波数を確
定する発振周波数確定手段とを備えることを特徴とする
スペクトラム拡散された信号の復調装置。7. The demodulator for a spread spectrum signal according to claim 3, wherein the synchronization control circuit further detects one oscillation frequency of the oscillator at which the detection result of the correlation value is equal to or higher than a predetermined level. After that, a correlation value increasing / decreasing trend detecting means for detecting the increasing / decreasing tendency of the correlation value by comparing the correlation value detection results at frequencies before and after the oscillation frequency, and a direction in which the correlation value increases The correlation value peak detecting means for detecting the peak of the correlation value by shifting the oscillation frequency of the oscillator to a frequency of, and the operation of the spreading code dividing means is stopped after the peak is detected, and the oscillation frequency of the oscillator is reduced. Setting value changing means for changing the frequency of the carrier in the minimum unit, and oscillating the oscillator with the peak value of the correlation value detected after the setting value is changed Spread spectrum signal demodulation device characterized by comprising an oscillation frequency determining means for determining the wavenumber. 【請求項８】 請求項３に記載のスペクトラム拡散され
た信号の復調装置において、 前記同期制御回路が、更に、前記相関値の検出結果が所
定レベル以上となる前記発振器の発振周波数の周波数範
囲を検出する第１の検出手段と、前記周波数範囲の検出
後にこの周波数範囲における前記相関値のピーク値を検
出する相関値ピーク検出手段と、前記拡散符号の分割手
段の分割数を減らすと共に、前記相関値のピーク値を検
出した前記発振器の発振周波数の前後の所定周波数範囲
内で前記発振器が発振する周波数の間隔を小さくする設
定値変更手段と、設定値変更後の前記相関値ピーク検出
手段と前記設定値変更手段の動作を繰り返して前記発振
器の発振周波数を確定する発振周波数確定手段とを備え
ることを特徴とするスペクトラム拡散された信号の復調
装置。8. The demodulator for a spread-spectrum signal according to claim 3, wherein the synchronization control circuit further controls a frequency range of an oscillation frequency of the oscillator in which a detection result of the correlation value becomes a predetermined level or more. First detecting means for detecting, a correlation value peak detecting means for detecting a peak value of the correlation value in the frequency range after detecting the frequency range, and reducing the number of divisions of the spreading code dividing means, Setting value changing means for reducing the interval between the frequencies at which the oscillator oscillates within a predetermined frequency range around the oscillation frequency of the oscillator which has detected the peak value of the value, the correlation value peak detecting means after the setting value is changed, and Oscillation frequency determination means for determining the oscillation frequency of the oscillator by repeating the operation of the set value changing means, No. demodulator. 【請求項９】 請求項３に記載のスペクトラム拡散され
た信号の復調装置において、 前記同期制御回路が、更に、前記相関値の検出結果が所
定レベル以上となる前記発振器の発振周波数の周波数範
囲を検出する第１の検出手段と、前記周波数範囲の検出
後にこの周波数範囲における前記相関値のピーク値を検
出する相関値ピーク検出手段と、前記拡散符号の分割手
段の分割動作を停止させると共に、前記相関値のピーク
値を検出した前記発振器の発振周波数の前後の所定周波
数範囲内で前記発振器が発振する周波数の間隔を小さく
する設定値変更手段と、設定値変更後の前記相関値ピー
ク検出手段と前記設定値変更手段の動作を繰り返して前
記発振器の発振周波数を確定する発振周波数確定手段と
を備えることを特徴とするスペクトラム拡散された信号
の復調装置。9. The demodulator for a spread spectrum signal according to claim 3, wherein the synchronization control circuit further controls a frequency range of an oscillation frequency of the oscillator in which a detection result of the correlation value is equal to or higher than a predetermined level. First detection means for detecting, correlation value peak detection means for detecting the peak value of the correlation value in the frequency range after the detection of the frequency range, and stopping the dividing operation of the spreading code dividing means, Setting value changing means for reducing the interval of the frequency at which the oscillator oscillates within a predetermined frequency range around the oscillation frequency of the oscillator which has detected the peak value of the correlation value, and the correlation value peak detecting means after the setting value has been changed; Oscillation frequency determining means for determining the oscillation frequency of the oscillator by repeating the operation of the set value changing means. Demodulator of signals. 【請求項１０】 請求項１から９の何れか１項に記載の
スペクトラム拡散された信号の復調装置において、 前記相関器が、前記拡散符号の発生器が発生した拡散符
号を所定の同一位相に保持したまま、前記拡散符号の複
数の周期分の相関値を算出し、その平均値を前記拡散符
号の所定位相における相関値として検出することを特徴
とするスペクトラム拡散された信号の復調装置。10. The apparatus for demodulating a spectrum-spread signal according to claim 1, wherein the correlator sets the spread code generated by the spread code generator to a predetermined same phase. An apparatus for demodulating a spread-spectrum signal, wherein a correlation value for a plurality of periods of the spread code is calculated while holding the spread code, and an average value thereof is detected as a correlation value at a predetermined phase of the spread code. 【請求項１１】 請求項１から１０の何れか１項に記載
のスペクトラム拡散された信号の復調装置において、 前記ミキサと相関器が並列に２系統設けられており、前
記ミキサの一方には前記発振器の出力をそのまま入力
し、他方には前記発振器の出力を９０°移相して入力
し、２つの相関器の出力を加算した値を相関値として検
出することを特徴とするスペクトラム拡散された信号の
復調装置。11. The apparatus for demodulating a spread spectrum signal according to claim 1, wherein two systems of the mixer and the correlator are provided in parallel, and one of the mixers is provided with the mixer. The output of the oscillator is input as it is, and the other output is input by shifting the phase of the oscillator by 90 °, and the value obtained by adding the outputs of the two correlators is detected as a correlation value. Signal demodulation device. 【請求項１２】 請求項１から１１の何れか１項に記載
のスペクトラム拡散された信号の復調装置において、 前記相関器にマッチトフィルタを使用したことを特徴と
するスペクトラム拡散された信号の復調装置。12. The demodulation apparatus for a spread spectrum signal according to claim 1, wherein a matched filter is used for the correlator. apparatus. 【請求項１３】 請求項１から１１の何れか１項に記載
のスペクトラム拡散された信号の復調装置において、 前記相関器にスライディング相関器を使用したことを特
徴とするスペクトラム拡散された信号の復調装置。13. The demodulation device for a spread spectrum signal according to claim 1, wherein a sliding correlator is used as said correlator. apparatus.
JP11198690A 1999-07-13 1999-07-13 Demodulating device for signal undergoing spectrum spread Withdrawn JP2001028556A (en)

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Application Number Priority Date Filing Date Title
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Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
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JP2001028556A true JP2001028556A (en) 2001-01-30

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007504731A (en) * 2003-09-01 2007-03-01 セクレタリー オブ ステイト フォー ディフェンス Modulation signal of satellite navigation system
JP2007158930A (en) * 2005-12-07 2007-06-21 Fujitsu Ltd Automatic frequency control method, automatic frequency control program and automatic frequency control apparatus
JP2008177945A (en) * 2007-01-19 2008-07-31 Nippon Dempa Kogyo Co Ltd Signal processing section and radio
JP2009273152A (en) * 2002-03-25 2009-11-19 Interdigital Technol Corp Method for blind code detection

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009273152A (en) * 2002-03-25 2009-11-19 Interdigital Technol Corp Method for blind code detection
US8681744B2 (en) 2002-03-25 2014-03-25 Interdigital Technology Corporation Method and apparatus for blind code detection
JP2007504731A (en) * 2003-09-01 2007-03-01 セクレタリー オブ ステイト フォー ディフェンス Modulation signal of satellite navigation system
JP4850065B2 (en) * 2003-09-01 2012-01-11 セクレタリー オブ ステイト フォー ディフェンス Modulation signal of satellite navigation system
JP2007158930A (en) * 2005-12-07 2007-06-21 Fujitsu Ltd Automatic frequency control method, automatic frequency control program and automatic frequency control apparatus
JP2008177945A (en) * 2007-01-19 2008-07-31 Nippon Dempa Kogyo Co Ltd Signal processing section and radio

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