JPH04192829A - Demodulating equipment for spread spectrum signal - Google Patents
Demodulating equipment for spread spectrum signalInfo
- Publication number
- JPH04192829A JPH04192829A JP2324451A JP32445190A JPH04192829A JP H04192829 A JPH04192829 A JP H04192829A JP 2324451 A JP2324451 A JP 2324451A JP 32445190 A JP32445190 A JP 32445190A JP H04192829 A JPH04192829 A JP H04192829A
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- signal
- frequency
- spread spectrum
- predetermined
- sequence
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- 238000001228 spectrum Methods 0.000 title claims abstract description 24
- 230000010355 oscillation Effects 0.000 claims abstract description 13
- 238000006243 chemical reaction Methods 0.000 claims description 12
- 230000001360 synchronised effect Effects 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 abstract description 6
- 230000006866 deterioration Effects 0.000 abstract 1
- 238000009792 diffusion process Methods 0.000 abstract 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 12
- 239000010931 gold Substances 0.000 description 12
- 229910052737 gold Inorganic materials 0.000 description 12
- 230000000694 effects Effects 0.000 description 10
- 238000000034 method Methods 0.000 description 9
- 238000001514 detection method Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 4
- 230000003111 delayed effect Effects 0.000 description 2
- 206010068829 Overconfidence Diseases 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
Abstract
Description
【発明の詳細な説明】
(産業上の利用分野)
本発明はスペクトラム拡散信号の復調装置に関し、殊に
ド1ブラ効果、又は送信側発振器の周波数変動等により
受信信号の搬送波周波数の変化が生じた場合、或いは受
信側の局部発振周波数が変動した場合であっても、これ
を補償して正確に復調すべき情報データを得ることが可
能なスペクトラム拡散信号の復調装置に関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a demodulator for a spread spectrum signal, and in particular to a demodulator for a spread spectrum signal, in which a change in the carrier frequency of a received signal occurs due to the Doubler effect or frequency fluctuation of a transmitting oscillator. The present invention relates to a spread spectrum signal demodulation device that can compensate for this and obtain information data to be accurately demodulated even when the local oscillation frequency on the receiving side fluctuates.
(従来技術)
スペクトラム拡散過信方式は比較的広い周波数帯域に伝
送すべき情報信号を拡散して伝送するため単位周波数カ
たりの伝送電力が小さく、他の通信に対して妨害を与え
ることが殆どないのみならず外部雑音の影響を受けにく
い点及び秘匿性に優れる点等に多くの特徴がある。(Prior art) The spread spectrum overconfidence method spreads the information signal to be transmitted over a relatively wide frequency band and transmits it, so the transmission power per unit frequency is small and there is almost no interference with other communications. It also has many features such as being less susceptible to external noise and having excellent confidentiality.
無線通信路を介してスペクトラム拡散通信を行う方法と
しては第4図に示すものが一般的である。The method shown in FIG. 4 is a common method for performing spread spectrum communication via a wireless communication channel.
即ち、この通信方法は送信側Tでは発振器lで周波数t
@の搬送波を生成すると共に、乗算器2を使用して伝送
すべき情報データDを前記搬送波で変調し、乗算器3を
使用してその変調信号を所要ビット長の疑似雑音(以下
、PN系列と称する)で乗積変調することによって前記
情報データDをスペクトラム拡散した後、無線通信路を
介して受信側Rに送出する。That is, in this communication method, on the transmitting side T, the oscillator l uses the frequency t.
At the same time as generating a carrier wave of After the information data D is spectrum-spread by multiplicative modulation, it is sent to the receiving side R via a wireless communication channel.
一方、受信側Rでは局部発振器4で周波数fLのローカ
ル信号を発生せしめると共に、PN系列発生器5で送信
側Tに於いて使用したものと同一のPN系列を発生せし
め、送信側Tから送致されたスペクトラム拡散信号と前
記ローカル信号とをミキサ6で周波数混合することによ
って前記スペクトラム拡散信号を周波数f@−ft(以
下、中間周波数r+ と称する)の中間周波信号に変換
した後、データ復調部7及び遅延ロブクループ回路(以
下、DLLと称する)8各々に出力する。データ復調部
7は乗算器9を使用して前記PN系列で中間周波信号を
逆拡散すると共に、その逆拡散せしめた信号から前記情
報データDの伝送速度に基づく帯域幅で、その中心周波
数がf−の信号成分をバンドパスフィルタlOで抽出し
た後、その抽出信号を検波器11で包絡線検波し、周波
数f1のキャリア成分を除去することによって元の情報
データDを復調する。又、受信側Rはレベル検出器12
を使用して前記情報データの絶対値を求めると共に、こ
の絶対値信号を情報データのデータ周期毎に積分してそ
の信号レベルが所定値を越えたか否かを判断し、そのレ
ベルが所定値を越えるまでPN系列発生器5が発生する
PN系列を1ビツトシフトして送信側T及び受信側R各
々に於いて使用するPN系列を互いに同期せしめる。更
に、この方法て送信側TのPN系列と受信側RのPN系
列との同期をとった後、受信側RはDDL8を使用して
この同期状態を保持するように、例えばPN系列発生器
5が発生せしめるPN系列のシフトクロック周波数を調
整する。On the other hand, on the receiving side R, the local oscillator 4 generates a local signal of frequency fL, and the PN sequence generator 5 generates the same PN sequence as that used at the transmitting side T, which is sent from the transmitting side T. After converting the spread spectrum signal into an intermediate frequency signal of frequency f@-ft (hereinafter referred to as intermediate frequency r+) by frequency-mixing the spread spectrum signal and the local signal in the mixer 6, the data demodulator 7 and a delay loop circuit (hereinafter referred to as DLL) 8, respectively. The data demodulation unit 7 despreads the intermediate frequency signal using the PN sequence using the multiplier 9, and uses the despread signal to obtain a center frequency of f with a bandwidth based on the transmission speed of the information data D. After extracting the signal component of − with the bandpass filter IO, the extracted signal is envelope-detected with the wave detector 11, and the original information data D is demodulated by removing the carrier component of the frequency f1. Also, the receiving side R has a level detector 12.
The absolute value of the information data is determined using The PN sequence generated by the PN sequence generator 5 is shifted by 1 bit until the PN sequence exceeds 1, and the PN sequences used on the transmitting side T and the receiving side R are synchronized with each other. Further, after synchronizing the PN sequence of the transmitter T and the PN sequence of the receiver R using this method, the receiver R uses the DDL 8 to maintain this synchronization state, e.g. by the PN sequence generator 5. Adjust the shift clock frequency of the PN series generated by the PN sequence.
しかし、上述のような復調方法では送信側、又は受信側
或いは両方が高速で移動する場合ドツプラ効果により受
信信号の周波数が変化し、該受信信号をPN系列で逆拡
散した信号の周波数が前記バンドパスフィルタの通過帯
域を外れて結果的に元の情報データを復調することがで
きないと云う問題があった。又、同様の問題は送信側に
於いて生成する搬送波、または受信側に於いて生成する
ローカル信号の周波数に変動がある場合にも発生し、特
に情報データの伝送速度が遅く、且つ搬送波の周波数が
極めて高い場合に顕著であった。更に、この問題を解決
する方法としてドブブラ効果等による搬送波の周波数変
動を加味して前記バンドパスフィルタの通過帯域を広く
することが考えられるが、その分S/Nが悪化するため
実用的ではない。However, in the above-described demodulation method, when the transmitting side, the receiving side, or both move at high speed, the frequency of the received signal changes due to the Doppler effect, and the frequency of the signal obtained by despreading the received signal with a PN sequence is in the band. There was a problem in that the original information data could not be demodulated as a result of being out of the pass band of the pass filter. Similar problems also occur when the frequency of the carrier wave generated on the transmitting side or the local signal generated on the receiving side fluctuates, especially when the transmission speed of information data is slow and the frequency of the carrier wave varies. This was noticeable when the amount was extremely high. Furthermore, as a way to solve this problem, it is conceivable to widen the passband of the bandpass filter by taking into account the frequency fluctuation of the carrier wave due to the Dobbler effect, etc., but this is not practical because the S/N deteriorates accordingly. .
従来、この問題を解決する方法としては第5図に示すよ
うに、送信側Tでは情報データを送信するための搬送波
とは別に連続波CWを送信する。Conventionally, as a method for solving this problem, as shown in FIG. 5, the transmitting side T transmits a continuous wave CW separate from a carrier wave for transmitting information data.
一方、受信側Rではこの連続波CWの受信周波数をU測
するためのドフブラ検出器13を設け、その観測周波数
と規定周波数との差に基づいて局部発振器4が発生せし
めるローカル信号の周波数を補正してPN系列で逆拡散
した信号の周波数が常にバンドパスフィルタの中心周波
数f+になるようにしていた。On the other hand, on the receiving side R, a Doffbra detector 13 is provided to measure the reception frequency of this continuous wave CW, and the frequency of the local signal generated by the local oscillator 4 is corrected based on the difference between the observed frequency and the specified frequency. The frequency of the signal despread using the PN sequence is always set to the center frequency f+ of the bandpass filter.
しかしながら、上述のスペクトラム拡散信号通信方式で
は情報データを通信するための送信機及び受信機以外に
ドフブラ効果等の影響を測定するための送信機及び受信
機が必要なため装置が非常に複雑高価となるばかりでな
く、周波数利用効率が悪化すると云う欠点があった。However, the above-mentioned spread spectrum signal communication method requires a transmitter and receiver for measuring the influence of the Doffbra effect in addition to the transmitter and receiver for communicating information data, making the equipment extremely complicated and expensive. In addition to this, there was also the drawback that frequency utilization efficiency deteriorated.
(発明の目的)
本発明は上述した如きドブブラ効果、又は送信側の搬送
周波数の変動等を伴う場合のスペクトラム拡散通信方式
の問題点を解決するためになされたものであって、装置
の大型化を伴わずしかも周波数の利用効率を疎外するこ
となく元の情報データを得ることが可能なスペクトラム
拡散信号の復調装置を提供することを目的とする。(Object of the Invention) The present invention has been made in order to solve the problems of the spread spectrum communication system when accompanied by the above-mentioned Dobbler effect or fluctuations in the carrier frequency on the transmitting side, It is an object of the present invention to provide a demodulating device for a spread spectrum signal, which can obtain original information data without causing interference and without detracting from frequency utilization efficiency.
(発明の概要)
上述の目的を達成するため、本発明に於いては以下の如
き手段を講する。(Summary of the Invention) In order to achieve the above object, the present invention takes the following measures.
即ち、受信信号を送信側と同上PN系列で逆拡散し、搬
送波に重畳したスペクトラム拡散信号を復調する装置に
於いて、周波数変換手段を設けると共に、互いに中心周
波数が異なり且つ通過帯域幅が等しい複数のバンドパス
フィルタで逆拡散信号、又はこの信号を所要の周波数に
変換した信号から所定の周波数の信号を抽出し、前記各
バンドパスフィルタの出力信号レベルの最大値が所定値
を越えることを検出して送受信間のPN系列の同期をと
ると共に、前記所定値を越えた信号を出力したバンドパ
スフィルタの中心周波数に基づいて前記周波数変換手段
に設けた局部発振器の発振周波数を所定の周波数に補正
するように構成する。That is, in a device that despreads a received signal using the same PN sequence as described above on the transmitting side and demodulates a spread spectrum signal superimposed on a carrier wave, a frequency conversion means is provided, and a plurality of devices having different center frequencies and the same passband width are provided. A signal of a predetermined frequency is extracted from the despread signal or a signal obtained by converting this signal to a desired frequency using a band pass filter, and it is detected that the maximum value of the output signal level of each of the band pass filters exceeds a predetermined value. to synchronize the PN series between transmitter and receiver, and correct the oscillation frequency of the local oscillator provided in the frequency conversion means to a predetermined frequency based on the center frequency of the bandpass filter that outputs the signal exceeding the predetermined value. Configure it to do so.
(実施例)
以下、図示した実施例に基づいて本発明の詳細な説明す
る。(Example) Hereinafter, the present invention will be described in detail based on the illustrated example.
第1図は本発明の一実施例を示すスペクトラム拡散信号
の復調装置を示す構成図である。FIG. 1 is a block diagram showing a demodulating device for a spread spectrum signal according to an embodiment of the present invention.
ここでは動作の理解を容易にするために送信側を含めて
説明する。Here, in order to facilitate understanding of the operation, the transmission side will be included in the explanation.
同面に於いてTは送信側であって、周波数1゜575[
GHzlの搬送波を発生せしめる発振器1と、ヒブトレ
ート1.023[MHzlのlO段ゴールド符号を発生
せしめるPN系列発生器]4とを具えると共に、乗算i
12を使用してビブトレー)カ50 [b I t/s
]の伝送すべき情報データDで前記搬送波を変調し、乗
算器3を使用してその変調信号を前記ゴールド符号で乗
積変調することによって前記データDをスペクトラム拡
散した後、無wA通信路を介して復調装置wに送出する
ように構成する。On the same plane, T is the transmitting side, and the frequency is 1°575[
It comprises an oscillator 1 that generates a carrier wave of GHzl, a PN sequence generator with a Hibtorate of 1.023 [a PN sequence generator that generates a IO stage Gold code of MHzl], and a multiplier i
12 using bib tray) 50 [b I t/s
After modulating the carrier wave with the information data D to be transmitted and spreading the spectrum of the data D by multiply modulating the modulated signal with the Gold code using the multiplier 3, the non-wA communication channel is spread. The configuration is such that the signal is sent to the demodulator w via the demodulator w.
一方、Wは本発明に係る復調装置であって、周波数1.
512[GHzlの第10−カル信号を発生せしめる
VCXOI5、送信mTと同一のゴールド符号を発生せ
しめるPN系列発生器16及び周波数62. 545[
MHzlの第20−カル信号を発生せしめる局部発振W
117を具えると共に、送信側Tから送致された搬送周
波数1,575 [GHzlのスペクトラム拡散信号を
低雑音増幅器18及びイメージ除去用フィルタ+9を介
して抽出した信号と、前記第10−カル信号とをミキサ
20で周波数混合した後、中心周波数が63[Ml(Z
]で通過帯域幅がIO[MH2]のバンドパスフィル
タ21を使用して前記スペクトラム拡散信号を周波数が
63[M)+2]の第】中間周波信号に変換し、その中
間周波信号を増幅器22を介してデータ復調部23及び
DLL8の入力端子に夫々供給する。データ復調部23
は乗算器24を使用して前記第1中間周波信号を前記ゴ
ールド符号で逆拡散すると共に、該逆拡散信号を中心周
波数63[M)IZIで通過帯域幅が2[MH2]のバ
ンドパスフィルタ25及び増幅器26を介して生成した
信号と、前記第20−カル信号とをミキサ27で周波数
混合した後、中心周波数が455 [KHz]で通過帯
域幅がIOQ[Hz)のバンドパスフィルタ28を使用
して前記逆拡散信号を周波数が455 [KHz]の第
2中間周波信号に変換し、その第2中間周波信号を増幅
器29及び検波器30を介して元の情報データを復調す
るように接続する。DLL8は上述した従来のものと同
様に送信側Tのゴールド符号と、PN系列発生器8のゴ
ールド符号との同期状態を保持するように、例えばPN
系列発生器8が発生せしめるゴールド符号のシフトクロ
ック周波数を調整するように接続する。又、復調装WW
は前記ミキサ27の出力信号を同期捕捉部31に供給し
て、該同期捕捉部31から制御信号を補正回路32を介
して前記VCXOI5の入力端子に、又同期捕捉部31
から検出信号をタイミング発生回路33を介してPN系
列発生器】6の入力端子に夫々供給するように接続する
。前記同期捕捉部31は通過帯域幅が100[H4Fで
中心周波数が450,450、 1. 450. 2、
・・・、459.9.46o[KHzlのバンドパスフ
ィルタF + 乃至F +m+ ヲ具えると共に、前記
ミキサ27の出力信号をバンドパスフィルタF1乃至F
1111各々を介して判定部34に供給することによ
って前記制御信号及び検出信号を出力するように構成す
る。On the other hand, W is a demodulator according to the present invention, which has a frequency of 1.
VCXOI 5 for generating a 10th-cal signal of 512 [GHzl], a PN sequence generator 16 for generating a Gold code identical to the transmitted mT, and a frequency 62. 545 [
Local oscillation W that generates the 20th-cal signal of MHz
117, a signal extracted from a spread spectrum signal with a carrier frequency of 1,575 GHz sent from the transmitting side T via a low noise amplifier 18 and an image removal filter +9, and the 10th-cal signal. After frequency mixing with the mixer 20, the center frequency becomes 63 [Ml(Z
], the spread spectrum signal is converted into an intermediate frequency signal with a frequency of 63[M)+2] using a bandpass filter 21 with a passband width of IO[MH2], and the intermediate frequency signal is passed through an amplifier 22. The data is supplied to the input terminals of the data demodulation section 23 and the DLL 8 via the data demodulator 23 and the DLL 8, respectively. Data demodulation section 23
uses a multiplier 24 to despread the first intermediate frequency signal with the Gold code, and passes the despread signal to a bandpass filter 25 with a center frequency of 63 [M)IZI and a passband width of 2 [MH2]. After frequency-mixing the signal generated through the amplifier 26 and the 20th-cal signal in a mixer 27, a bandpass filter 28 with a center frequency of 455 [KHz] and a passband width of IOQ [Hz] is used. The despread signal is converted into a second intermediate frequency signal having a frequency of 455 KHz, and the second intermediate frequency signal is connected to an amplifier 29 and a detector 30 so as to demodulate the original information data. . The DLL 8 maintains the synchronization state between the Gold code of the transmitting side T and the Gold code of the PN sequence generator 8, as in the conventional one described above.
The connection is made so as to adjust the shift clock frequency of the Gold code generated by the sequence generator 8. Also, demodulator WW
supplies the output signal of the mixer 27 to the synchronization acquisition section 31, and sends the control signal from the synchronization acquisition section 31 to the input terminal of the VCXOI 5 via the correction circuit 32.
The detection signals from the PN sequence generator 6 are connected to be supplied to the input terminals of the PN sequence generator 6 via the timing generating circuit 33, respectively. The synchronization acquisition unit 31 has a passband width of 100[H4F and a center frequency of 450,450, 1. 450. 2,
..., 459.9.46o [KHzl] band pass filters F + to F +m+ are provided, and the output signal of the mixer 27 is passed through the band pass filters F1 to F
The control signal and the detection signal are outputted by supplying them to the determination unit 34 via the respective signals 1111 and 1111.
このように構成する復調装置tWは以下のように動作す
る。The demodulator tW configured as described above operates as follows.
即ち、復調装WIWは同期捕捉部3Iがバンドパスフィ
ルタFl乃至F +@+各々によって前記第2中間周波
信号から周波数が450.450.1゜450.2、・
・・、459.9.460 [KHzlの信号を抽出し
、各周波数毎にその信号レベルが所定値を越えたか否か
を判定部34で検出すると共に前記レベルが所定値を越
えるまで検出信号を出力してPN系列発生器16が発生
するゴールド符号を前記情報データのビット周期毎に1
ビツト/フ卜せしめて送信側Tと復調装置wとのゴール
ド符号を互いに同期せしめる。又、判定部34は前記所
定値を越えた信号を出力したバンドパスフィルタを判定
すると共に、そのフィルタの中心周波数の値を制御信号
として補正回路32に供給し、2キサ27が出力せしめ
る第2中間周波信号の周波数が常に455 [KHzl
になるようにvcX015の発振周波数を調整する。That is, in the demodulator WIW, the synchronization acquisition unit 3I converts the frequency from the second intermediate frequency signal to 450.450.1°, 450.2, .
..., 459.9.460 [KHz] signal is extracted, and the determination unit 34 detects whether or not the signal level exceeds a predetermined value for each frequency, and the detection signal is continued until the level exceeds the predetermined value. The gold code output and generated by the PN sequence generator 16 is 1 for each bit period of the information data.
The bits/digits are set to synchronize the Gold codes of the transmitter T and the demodulator w with each other. Further, the determination unit 34 determines the bandpass filter that outputs a signal exceeding the predetermined value, and supplies the value of the center frequency of that filter to the correction circuit 32 as a control signal, and the second The frequency of the intermediate frequency signal is always 455 [KHzl]
Adjust the oscillation frequency of vcX015 so that
従って、この復調装置Wによればスペクトラム拡散信号
がドブプラ効果の影響を受けて受信周波数が変化して前
記第2中間周波信号の周波数がバンドパスフィルタ28
の通過帯域を外れても、前記受信周波数の偏移量が±5
[KHzlであればバンドパスフィルタF1乃至F
Ie+ の何れかの出力端から第2中間周波数に変換し
た逆拡散信号の最大値を検出することができるから、常
に送信側と受信側とのゴールド符号を互いに同期せしめ
ることができ、又バンドパスフィルタ28の通過帯域を
広げることなく第2中間周波に変換した逆拡散信号の周
波数が常にバンドパスフィルタ28の中心周波数455
[KHz]になるようにVCX015の発振周波数を
制御するから、S/Nを劣化せしめることな(元の情報
データを復調することができる。Therefore, according to this demodulator W, the reception frequency of the spread spectrum signal changes due to the influence of the Dobppler effect, and the frequency of the second intermediate frequency signal is changed to the frequency of the second intermediate frequency signal by the bandpass filter 28.
Even if it is out of the passband, the deviation of the receiving frequency is ±5.
[If KHzl, band pass filters F1 to F
Since the maximum value of the despread signal converted to the second intermediate frequency can be detected from either output end of the Ie+, the Gold codes on the transmitting side and the receiving side can always be synchronized with each other, and the bandpass The frequency of the despread signal converted to the second intermediate frequency without widening the passband of the filter 28 is always the center frequency 455 of the bandpass filter 28.
Since the oscillation frequency of the VCX015 is controlled to be [KHz], the original information data can be demodulated without deteriorating the S/N.
又、第2図は本発明の変形実施例であって、通過帯域幅
が100[Hz]で中心周波数が450.450、 1
. 450. 2、・・・、459,9.460 [K
HzlのバンドパスフィルタF口乃至FN@1、周波数
62. 545 [MH2]の第30−カル信号を発生
せしめる局部発振器35、実効値生成回路R,乃至R1
111、ミキサ36.37及び移相器38を第1図に示
した同期捕捉部31に設けて、前記増幅器26の出力信
号と、前記第30−カル信号とをミキサ36で周波数混
合して該増幅器26の出力信号を周波数455[KH2
]の第3中間周波信号に変換した後、バンドパスフィル
タF1乃至F I@I に並列に入力すると共に、前記
増幅器26の出力信号と、前記移相器38を使用して前
記第30−カル信号の位相をπ/2[rad]遅らせた
信号とをミキサ37で周波数混合して前記第3中間周波
信号の位相をπ/2[rad]遅らせた信号に変換した
後、バッドパスフィルタFl+乃至F 11@1に並列
に入力する。又、前記実効値生成回路R1を使用してバ
ンドパスフィルタFマ及びFl+の出力信号を夫々2乗
して互いに加算した後に平方根を求めて判定部34に供
給すると共に、以下同様に実効値生成回路R2乃至RI
I+毎に所定のバンドパスフィルタの出力信号ヲ夫々2
乗して互いに加算した後に平方根を求めて判定部34に
供給することによって前記制御信号及び検出信号を出力
するように構成する。FIG. 2 shows a modified embodiment of the present invention, in which the passband width is 100 [Hz] and the center frequency is 450.450.1
.. 450. 2,...,459,9.460 [K
Hzl bandpass filter F to FN@1, frequency 62. Local oscillator 35 that generates the 30th-cal signal of 545 [MH2], effective value generation circuits R, to R1
111, mixers 36 and 37, and a phase shifter 38 are provided in the synchronization acquisition section 31 shown in FIG. The output signal of the amplifier 26 is set to a frequency of 455 [KH2
] is inputted in parallel to the bandpass filters F1 to FI@I, and the output signal of the amplifier 26 and the phase shifter 38 are used to convert the 30th intermediate frequency signal into the third intermediate frequency signal. A mixer 37 mixes the frequency of the signal with the signal whose phase is delayed by π/2 [rad] and converts the third intermediate frequency signal into a signal whose phase is delayed by π/2 [rad]. Input in parallel to F11@1. Further, using the effective value generation circuit R1, the output signals of the bandpass filters F and Fl+ are respectively squared and added together, and then the square root is determined and supplied to the determination section 34, and the effective value is generated in the same manner. Circuit R2 to RI
2 output signals of a predetermined bandpass filter for each I+
The control signal and the detection signal are output by multiplying the signals and adding them to each other, and then calculating the square root and supplying the square root to the determination unit 34.
この復調装置wによれば、増幅器26の出力信号、即ち
第1中間周波信号を逆拡散せしめた信号の実数項成分と
虚数項成分とを夫々求めた後、各成分毎に周波数が45
0.450.1.450゜2、・・・、459.9.4
60[KHz]の信号を抽出し、各周波数毎にその信号
の実効値を求めてその実効値が所定値を越えたか否かを
判定部34で検出すると共に、前記実効値が所定値を越
えるまで検出信号を出力し、又判定部34は前記所定値
を越えた信号を出力した実行値生成回路に信号を供給す
るバンドパスフィルタの中心周波数の値を制御信号とし
て補正回路32に供給し、第2中間周波信号の周波数が
常にバンドパスフィルタ28の中心周波数455 [K
H2]になるようにVCXOI5の発振周波数を制御す
るから、例えば第1図に示した実施例に於いて局部発振
器17の第20−カル信号と逆拡散信号との位相が互t
1にπ [rad]異なることによって本来ノインド!
イスフィルタFlから出力すべき信号のレベルを零にす
ることなく、即ち第30−カル信号と逆拡散信号との位
相差に拘らず前記判定部34に入力せしめる信号のレベ
ルを一定にすることができ、判定部34の判定結果を正
確にすることができる。According to this demodulator w, after obtaining the real term component and the imaginary term component of the output signal of the amplifier 26, that is, the signal obtained by despreading the first intermediate frequency signal, the frequency of each component is set to 45.
0.450.1.450°2,..., 459.9.4
A signal of 60 [KHz] is extracted, the effective value of the signal is determined for each frequency, and the determination unit 34 detects whether or not the effective value exceeds a predetermined value. The determination unit 34 outputs a detection signal up to the predetermined value, and the determination unit 34 supplies the correction circuit 32 with the value of the center frequency of the bandpass filter that supplies the signal to the effective value generation circuit that outputs the signal exceeding the predetermined value as a control signal, The frequency of the second intermediate frequency signal is always equal to the center frequency 455 [K
Since the oscillation frequency of the VCXOI 5 is controlled so that, for example, in the embodiment shown in FIG.
By being different from π [rad] to 1, it is originally noindo!
It is possible to keep the level of the signal input to the determination unit 34 constant without reducing the level of the signal to be output from the chair filter Fl to zero, that is, regardless of the phase difference between the 30th-cal signal and the despread signal. This allows the determination result of the determination unit 34 to be accurate.
尚、上述の実施例に於いては通過帯域幅が100 [H
zlで中心周波数が450.450.1゜4502、・
・・、459.9.460 [KHz]のバンドパスフ
ィルタを、又はこれ等のバンドパスフィルタを一組、同
期捕捉部に設けたが、各/インドパスフィルタの通過帯
域幅、中心周波数及び同期捕捉部に設けるバンドパスフ
ィルタの数はこれに限る必要はない。即ち、同期捕捉部
に供給する信号の中心周波数をf、[Hzl、ドフブラ
効果等の影響によって生じる該信号の最大周波数偏移を
1.i [Hzl、伝送すべき情報データのビットレ
ートをrr [bps]とした場合、同期捕捉部に設
けるバンドパスフィルタ各々の通過帯域幅B[Hzl
は弐B≧2fr[Hzlから求めれば良く、又ステツブ
周波数rs [H2]を式Off、≦Bから求めれば
、前記パントノくスフイルりの中心周波数は夫h rx
fa+fw−f4+ fs、 f、−1d+2fa
、 fx fd+3fa、・・・、 fw+fa−2
fs、 fx+fn−fa、 rx+ra[Hzl
とすれば、ドフブラ効果等の影響を受けて該同期捕捉
部に供給せしめる信号の中心周波数が変動しても同期捕
捉部は常に前記検出信号、及び制御信号を出力すること
ができる。In the above embodiment, the passband width is 100 [H
zl and the center frequency is 450.450.1°4502,・
..., a bandpass filter of 459.9.460 [KHz] or a set of such bandpass filters is provided in the synchronization acquisition section, but the passband width, center frequency, and synchronization of each/indopass filter are The number of bandpass filters provided in the capture section does not need to be limited to this. That is, the center frequency of the signal supplied to the synchronization acquisition section is f, [Hzl], and the maximum frequency deviation of the signal caused by the influence of the Doffbra effect, etc. is 1. i [Hzl], and when the bit rate of the information data to be transmitted is rr [bps], the passband width of each bandpass filter provided in the synchronization acquisition section is B [Hzl
can be calculated from 2B≧2fr[Hzl, and if the stepping frequency rs [H2] is calculated from the formula Off, ≦B, then the center frequency of the pantone square can be calculated as h rx
fa+fw-f4+ fs, f, -1d+2fa
, fx fd+3fa,..., fw+fa-2
fs, fx+fn-fa, rx+ra[Hzl
If so, the synchronization acquisition section can always output the detection signal and the control signal even if the center frequency of the signal supplied to the synchronization acquisition section changes due to the influence of the Doffbra effect or the like.
又、上述の実施例に於いては受信信号を第1中間周波信
号に変換した後、送信側と同じゴールド符号で逆拡散し
、更に第2中間周波信号に変換した信号を同期捕捉部に
入力せしめて送受信間のゴールド符号を同期せしめるた
めの検出信号をタイミング発生回路を介してPN系列発
生器に供給すると共に、第1中間周波信号に変換する際
に使用する発振器の発振周波数を補正するための制御信
号を出力するようにしたが、本発明はこれに限る必要は
ない。例えば、第3図に示すように受信信号を逆拡散し
た信号を同期捕捉部31に入力せしめて前記検出信号を
タイミング発生回路33を介してPN系列発生器16に
供給すると共に、ミキサ20を使用して前記逆拡散信号
をベース、インド信号に変換する際に、及びミキサ39
を使用して受信信号をベースバンド信号に変換する際に
使用するVCXO40の発振周波数を補正するための制
御信号を出力してバンドパスフィルタ28及びDLL8
各々に供給する信号の周波数を補正するようにしても良
く、又ミキサ41及び局部発振器42を使用して前記逆
拡散信号をベースバンド信号に変換した後に所定数n個
のバンドパスフィルタF1乃至F。に並列に入力するよ
うにしても良い。即ち、本発明は逆拡散する手段の前段
又は後段、或いはその両者に所定数の周波数変換手段を
設けて逆拡散した信号、又は前記逆拡散手段の後段に設
けた周波数変換手段の何れかの出力信号を同期捕捉部に
入力せしめて前記検出信号をタイミング発生回路を介し
てPN系列発生器に供給すると共に、逆拡散手段の後段
に設けた周波数変換手段に使用する発振器の発振周波数
の何れかを補正するための制御信号を出力するようにす
れば上述の実施例に限る必要がないことは自明であろう
。Furthermore, in the above embodiment, after converting the received signal to the first intermediate frequency signal, it is despread using the same Gold code as that on the transmitting side, and the signal further converted to the second intermediate frequency signal is input to the synchronization acquisition section. In order to at least supply a detection signal for synchronizing the Gold code between transmission and reception to the PN sequence generator via the timing generation circuit, and to correct the oscillation frequency of the oscillator used when converting into the first intermediate frequency signal. However, the present invention is not limited to this. For example, as shown in FIG. 3, a signal obtained by despreading the received signal is input to the synchronization acquisition section 31, and the detected signal is supplied to the PN sequence generator 16 via the timing generation circuit 33, and the mixer 20 is used. and a mixer 39 when converting the despread signal to a base Indian signal.
The band pass filter 28 and DLL 8
Alternatively, after converting the despread signal into a baseband signal using a mixer 41 and a local oscillator 42, a predetermined number n of bandpass filters F1 to F may be corrected. . may be input in parallel. That is, the present invention provides a signal despread by providing a predetermined number of frequency conversion means before or after the despreading means, or both, or the output of any one of the frequency conversion means provided after the despreading means. The signal is input to the synchronization acquisition section, the detection signal is supplied to the PN sequence generator via the timing generation circuit, and one of the oscillation frequencies of the oscillator used in the frequency conversion means provided after the despreading means is input. It is obvious that the present invention need not be limited to the above embodiments as long as a control signal for correction is output.
更に、本発明は同期捕捉部をディジタル・シグナル・プ
ロセッサ(DSP)等のディジタル回路で実現しても良
いことは自明であろう。Furthermore, it is obvious that the synchronization acquisition section of the present invention may be realized by a digital circuit such as a digital signal processor (DSP).
(発明の効果)
本発明は以上説明したように、スペクトラム拡散信号を
復調する際に、互いに中心周波数が異なると共に通過帯
域幅が等しい複数のバンドパスフィルタで逆拡散信号、
又は逆拡散信号を所要の周波数に変換した信号から所定
の周波数の信号を抽出し、前記各バンドパスフィルタの
出力信号レベルの最大値が所定値を越えることを検出し
て送受信間のPN系列の同期をとると共に、前記所定値
を越えた信号を出力したバンドパスフィルタの中心周波
数に基づいて周波数変換手段に設けた局部発振器の発振
周波数を所定の周波数に補正するようにしたので、 ド
ツプラ効果等の影響を受けて受信周波数等が変化しても
、又は局部発振器の周波数が変動してもS/Nを悪化さ
せることな(復調すべき情報データを得ることが可能な
スペクトラム拡散信号の復調装置を提供する上で著効を
奏する。(Effects of the Invention) As described above, the present invention, when demodulating a spread spectrum signal, uses a plurality of bandpass filters having different center frequencies and the same passband width to demodulate the despread signal,
Alternatively, a signal of a predetermined frequency is extracted from a signal obtained by converting a despread signal to a desired frequency, and the maximum value of the output signal level of each of the bandpass filters is detected to exceed a predetermined value, and the PN sequence between transmitting and receiving is detected. In addition to synchronizing, the oscillation frequency of the local oscillator provided in the frequency conversion means is corrected to a predetermined frequency based on the center frequency of the bandpass filter that outputs the signal exceeding the predetermined value, thereby eliminating the Doppler effect, etc. Even if the receiving frequency changes due to the influence of It is effective in providing the following.
第1図は本発明の一実施例を示す図、第2図及び第3図
は本発明の変形実施例を示す図、第4図及び第5図は従
来のスペクトラム拡散通信方法を説明する図である。
W・・・復調装置、21.25.28及びFl乃至F
+@I・・・バンドパスフィルタ、 15・・・vcx
o、16・・・PN系列発生器、+7・・・局部発振器
、18.22.26及び29・・・増幅器、19・・・
イメージ除去用フィルタ、20及び27・・・ミキサ、
23・・・データ復調部、8・・・DLL、24・・・
乗算器、3o・検波器、31・・同期捕捉部、32川補
正回路、33・・・タイミング発生回路、34・・・判
定部。
特許出願人 東洋通信機株式会社FIG. 1 is a diagram showing one embodiment of the present invention, FIGS. 2 and 3 are diagrams showing modified embodiments of the present invention, and FIGS. 4 and 5 are diagrams explaining a conventional spread spectrum communication method. It is. W... Demodulator, 21.25.28 and Fl to F
[email protected] filter, 15...vcx
o, 16...PN sequence generator, +7...local oscillator, 18.22.26 and 29...amplifier, 19...
Image removal filters, 20 and 27...mixers,
23...Data demodulation unit, 8...DLL, 24...
Multiplier, 3o/detector, 31... synchronization acquisition section, 32 river correction circuit, 33... timing generation circuit, 34... determination section. Patent applicant: Toyo Tsushinki Co., Ltd.
Claims (2)
送波に重畳したスペクトラム拡散信号を復調する装置に
於いて、前記逆拡散する手段の前段又は後段、或いはそ
の両者に所定数の周波数変換手段を設けると共に、互い
に中心周波数が異なり且つ通過帯域幅が等しい複数のバ
ンドパスフィルタで前記逆拡散した信号、又は前記逆拡
散する手段の後段に設けた周波数変換手段で生成した信
号から所定の周波数の信号を抽出し、前記各バンドパス
フィルタの何れかの出力信号レベルの最大値が所定値を
越えることを検出して送受信間のPN系列の同期をとる
と共に、前記所定値を越えた信号を出力したバンドパス
フィルタの中心周波数に基づいて前記周波数変換手段に
設けた局部発振器の発振周波数を所定の周波数に補正す
ることを特徴とするスペクトラム拡散信号の復調装置。(1) In a device that despreads a received signal using the same PN sequence as that on the transmitting side and demodulates a spread spectrum signal superimposed on a carrier wave, a predetermined number of frequencies are used before or after the despreading means, or in both. A conversion means is provided, and a predetermined signal is generated from the signal despread by a plurality of bandpass filters having different center frequencies and the same passband width, or a signal generated by a frequency conversion means provided after the despreading means. The frequency signal is extracted, and the maximum value of the output signal level of any one of the bandpass filters is detected to exceed a predetermined value, and the PN sequence between transmitting and receiving is synchronized, and the signal exceeding the predetermined value is detected. A demodulating device for a spread spectrum signal, characterized in that the oscillation frequency of a local oscillator provided in the frequency conversion means is corrected to a predetermined frequency based on the center frequency of a bandpass filter that outputs the signal.
送波に重畳したスペクトラム拡散信号を復調する装置に
於いて、前記逆拡散する手段の前段又は後段、或いはそ
の両者に所定数の周波数変換手段を設け、前記逆拡散し
た信号、又は前記逆拡散する手段の後段に設けた周波数
変換手段で生成した信号を2つに分岐すると共に、夫々
を互いに位相がπ/2[rad]異なる第1の信号と第
2の信号とを生成し、互いに中心周波数が異なり且つ通
過帯域幅が等しい複数のバンドパスフィルタを二組設け
て、一方の組のバンドパスフィルタ各々で前記第1の信
号から所定の周波数の信号を抽出し、他方の組のバンド
パスフィルタ各々で前記第2の信号から所定の周波数の
信号を抽出し、前記中心周波数が等しいバンドパスフィ
ルタの出力信号を夫々2乗して互いに加算した後に平方
根を求める手段で実効値を生成し、該実効値の最大値が
所定値を越えることを検出して送受信間のPN系列の同
期をとると共に、前記所定値を越えた実効値を生成した
手段に信号を供給するバンドパスフィルタの中心周波数
に基づいて前記周波数変換手段に設けた局部発振器の発
振周波数を所定の周波数に補正することを特徴とするス
ペクトラム拡散信号の復調装置。(2) In a device that despreads a received signal using the same PN sequence as that on the transmitting side and demodulates the spread spectrum signal superimposed on a carrier wave, a predetermined number of frequencies are used before or after the despreading means, or in both. A conversion means is provided, and the despread signal or the signal generated by the frequency conversion means provided after the despreading means is branched into two, and each of the signals is divided into two parts whose phases are different from each other by π/2 [rad]. 1 signal and a second signal, two sets of a plurality of band pass filters having mutually different center frequencies and equal pass band widths are provided, and each of the band pass filters of one set generates a signal from the first signal. extracting a signal of a predetermined frequency, extracting a signal of a predetermined frequency from the second signal using each of the other set of bandpass filters, and squaring the output signals of the bandpass filters having the same center frequency. After adding each other, an effective value is generated by means of calculating the square root, and by detecting that the maximum value of the effective value exceeds a predetermined value, synchronization of the PN sequence between transmitting and receiving is performed, and the effective value exceeding the predetermined value is detected. A demodulating device for a spread spectrum signal, characterized in that the oscillation frequency of a local oscillator provided in the frequency conversion means is corrected to a predetermined frequency based on the center frequency of a bandpass filter that supplies the signal to the means for generating the signal.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2324451A JPH04192829A (en) | 1990-11-27 | 1990-11-27 | Demodulating equipment for spread spectrum signal |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2324451A JPH04192829A (en) | 1990-11-27 | 1990-11-27 | Demodulating equipment for spread spectrum signal |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH04192829A true JPH04192829A (en) | 1992-07-13 |
Family
ID=18165962
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2324451A Pending JPH04192829A (en) | 1990-11-27 | 1990-11-27 | Demodulating equipment for spread spectrum signal |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH04192829A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH098699A (en) * | 1995-06-15 | 1997-01-10 | Nec Corp | Receiving equipment for spread spectrum signal |
-
1990
- 1990-11-27 JP JP2324451A patent/JPH04192829A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH098699A (en) * | 1995-06-15 | 1997-01-10 | Nec Corp | Receiving equipment for spread spectrum signal |
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