JPH04828A - Spread spectrum modulating/demodulating system - Google Patents
Spread spectrum modulating/demodulating systemInfo
- Publication number
- JPH04828A JPH04828A JP1314598A JP31459889A JPH04828A JP H04828 A JPH04828 A JP H04828A JP 1314598 A JP1314598 A JP 1314598A JP 31459889 A JP31459889 A JP 31459889A JP H04828 A JPH04828 A JP H04828A
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- Prior art keywords
- signal
- multiplier
- interference wave
- spreading code
- spread
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- 238000001228 spectrum Methods 0.000 title claims abstract description 46
- 238000000034 method Methods 0.000 claims description 35
- 230000005540 biological transmission Effects 0.000 claims description 12
- 238000004891 communication Methods 0.000 description 19
- 238000010586 diagram Methods 0.000 description 13
- 238000007796 conventional method Methods 0.000 description 7
- 230000001629 suppression Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 238000003379 elimination reaction Methods 0.000 description 2
- 240000002834 Paulownia tomentosa Species 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はスペクトル拡散変調復調方式に係り、特に、任
意の伝送手段又は記録再生媒体を介して得られたスペク
トル拡散信号中に含まれる種々の干渉波や雑音等を、復
調側において、比較的簡単な構成で大幅に抑圧、除去し
得るようにしたスペクトル拡散変調復調方式に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a spread spectrum modulation and demodulation method, and in particular, the present invention relates to a spread spectrum modulation and demodulation method, and in particular, to the spread spectrum modulation and demodulation method. The present invention relates to a spread spectrum modulation demodulation method that allows interference waves, noise, etc. to be significantly suppressed and removed with a relatively simple configuration on the demodulation side.
口技術的背景〕
スペクトル拡散(Spread Spectrum :
以下“SS”とも記載する)変調復調方式とは、変調側
では情報信号等を広帯域の雑音状の拡散符号により拡散
変調して、非常に広い周波数帯域に拡散すると共に、復
調側では変調側で使用する拡散符号と等価な拡散符号で
逆拡散する方式である。かかる変調復調方式を用いて通
信を行なうSS通信方式は、秘話性が非常に高く、外部
干渉や雑音、故意の妨害に強く、従来システムと共存で
き、しかも微弱な電力で送信でき、更に、疑似雑音符号
を変えることにより同一周波数帯域内に多重できる等々
多くの特長があるので、現在では単に通信機器分野にと
どまらず各分野での応用が進んでおり、民生機器への展
開も始まりつつある。[Technical Background] Spread Spectrum:
The modulation/demodulation method (hereinafter also referred to as "SS") means that the modulation side performs spread modulation on the information signal, etc. using a wideband noise-like spreading code to spread it over a very wide frequency band, and the demodulation side This is a method of despreading using a spreading code equivalent to the spreading code used. The SS communication method, which communicates using such a modulation and demodulation method, has extremely high confidentiality, is resistant to external interference, noise, and intentional interference, can coexist with conventional systems, can transmit with very low power, and is Since it has many features such as being able to multiplex within the same frequency band by changing the noise code, it is currently being applied not only to the communication equipment field but also to various fields, and is beginning to be applied to consumer equipment.
かかるSS通信方式を含むSS変調復調方式では、復調
側で干渉波を拡散する一方、信号を狭帯域化することに
より干渉軽減を行なっている。拡散復調後のDN比(1
ビット当りの信号電力対干渉電力密度比)Eb/Noは
、
(E b / N O) ” = R(C/ N6 )
−’士(C/I)”/Pg・・・・・・・・・・・・
(1)但し、R:ピットレート、Pg:処理利得C/’
に搬送波対干渉波電力比
で表わされる。Pgが十分大きければ、干渉波の影響は
雑音(ノイズ)の影響に比取して無視でき、干渉波が無
視できる場合には、SS信号を同一周波数帯で多重化し
て使用しても、SS通信方式の伝送効率の差はそれほど
無い。一方、雑音より干渉波の影響か支配的となると、
使用チャンネル数や伝送容量が干渉量により制限される
ため、SS通信方式の、欠点として伝送効率が著しく劣
化する。In SS modulation and demodulation systems including such SS communication systems, interference is reduced by spreading interference waves on the demodulation side and narrowing the signal band. DN ratio after spreading demodulation (1
The signal power per bit to interference power density ratio) Eb/No is: (E b / N O) ” = R (C/N6)
-'C/I”/Pg・・・・・・・・・・・・
(1) However, R: pit rate, Pg: processing gain C/'
is expressed as the carrier-to-interference wave power ratio. If Pg is sufficiently large, the influence of interference waves can be ignored compared to the influence of noise.If interference waves can be ignored, even if SS signals are multiplexed in the same frequency band and used, SS There is not much difference in transmission efficiency between communication methods. On the other hand, when the influence of interference waves becomes more dominant than that of noise,
Since the number of channels used and the transmission capacity are limited by the amount of interference, the SS communication system has a drawback that the transmission efficiency deteriorates significantly.
かかる干渉波の影響が支配的となる状況は、SS通信方
式を地上無線に適用した場合の“遠近問題”や衛星通信
のS S M A (5pread 5pectrun
Hulti−ple ACCeSS、非同期の多元接
続が可能な通信方式)において多数局が多元接続した場
合、あるいはSS信号と他の通信信号とのチャンネル共
用伝送等で顕著となる。Situations where the influence of such interference waves is dominant include the "near-far problem" when applying the SS communication system to terrestrial radio, and the SSMA (5pread, 5pectrun) problem in satellite communication.
This problem becomes noticeable when a large number of stations make multiple connections in Hulti-ple ACCeSS (a communication system that allows asynchronous multiple access), or when channel sharing is performed between SS signals and other communication signals.
こ従来の技術〕
SS変調復調方式の代表例であるSS通信方式には、前
記の如く大きな干渉軽減能力かあるので、他の通信方式
や同じSS通信方式との間で周波数帯域の共用か可能で
ある。しかるに同一周波数を共用すると、本質的に相互
干渉を避けられないので、他の局からの信号電力か非常
に大きくなれば、SS通信方式においても干渉(妨害)
波により性能か劣化してしまう。そこで、自局のSS信
号電力を増加させるとその信号の品質は向上するか、他
の信号に対する干渉か無視できなくなる。このような環
境下で、干渉軽減を実現しようとして、金遣にいくつか
の技術提案がなされている。This conventional technology] Since the SS communication method, which is a typical example of the SS modulation and demodulation method, has a large interference reduction ability as described above, it is possible to share the frequency band with other communication methods or with the same SS communication method. It is. However, if the same frequency is shared, mutual interference is essentially unavoidable, so if the signal power from other stations becomes extremely large, interference (jamming) will occur even in the SS communication system.
Performance deteriorates due to waves. Therefore, if the power of the SS signal of the own station is increased, the quality of the signal will improve, or the interference with other signals cannot be ignored. Under such circumstances, several technical proposals have been made in an attempt to reduce interference.
例えは、チャンネル共用伝送される信号か相互に干渉と
なる場合を想定し、干渉波が狭帯域信号のような特殊な
信号の場合には、G、C,L iu等により1979年
にNTCRecord p15〜p16にて報告された
BEF (帯域除去ろ波器)により除去する技術や、M
、J、 B ruvierによりIEEE Trans
、vol、Con−26,No、2にて報告された狭帯
域干渉波除去器により除去する技術がある。一方、広帯
域干渉波の場合は、並木淳冶氏より[コチャンネルFM
干渉除去技術。For example, assuming a case where signals transmitted in a shared channel interfere with each other, and if the interference wave is a special signal such as a narrowband signal, NTC Record p15 by G, C, Liu et al. The removal technology using BEF (band-elimination filter) reported on page 16 and M
, J. Bruvier, IEEE Trans.
There is a technique for removing interference waves using a narrowband interference wave remover, which was reported in , vol. Con-26, No. 2. On the other hand, in the case of broadband interference waves, Mr. Junji Namiki [Cochannel FM
Interference cancellation technology.
において、干渉を除去する技術の提案が昭和55年度に
なされている。In 1981, a proposal was made for a technology to eliminate interference.
以下、従来の代表的なSS干渉波除去方式について、図
面を参照し乍ら具体的に説明する。第5図は従来方式を
実現し得るSS変調復調装置の概略ブロック図であり、
同図(A)が変調部、(B)が復調部である。また、第
6図(A)〜(F)は各部の動作説明用周波数スペクト
ル図である。Hereinafter, a typical conventional SS interference wave removal method will be specifically explained with reference to the drawings. FIG. 5 is a schematic block diagram of an SS modulation and demodulation device that can realize the conventional method,
In the figure, (A) shows a modulation section, and (B) shows a demodulation section. Moreover, FIGS. 6(A) to 6(F) are frequency spectrum diagrams for explaining the operation of each part.
変調部においては、入力端子In+より、第6図(^)
のような、直流成分を含む低い周波数成分を有する情報
信号D(d(t))が乗算器2に供給される。この乗算
器2には、エンベロープが同図(B)の如きスペクトル
(メインローブのみ)を有する拡散符号信号P(tH以
下単に“P”とも記す)が拡散符号発生回路(PNG)
8から常時供給されているので、ここで情報信号りは
拡散変調され、更に次段のLPFIIにて拡散符号のサ
イドローブを除去されて、エンベロープが同図(C)の
ような周波数特性の拡散変調波D ss (= d(t
)P (t))となる。In the modulation section, from the input terminal In+, Fig. 6 (^)
An information signal D(d(t)) having a low frequency component including a DC component is supplied to the multiplier 2. This multiplier 2 receives a spreading code signal P (also simply referred to as "P" below tH) whose envelope has a spectrum (main lobe only) as shown in FIG.
Since the information signal is constantly supplied from 8, the information signal is spread modulated here, and the sidelobes of the spreading code are removed in the next stage LPFII, so that the envelope has a spread frequency characteristic as shown in the same figure (C). Modulated wave D ss (= d(t
)P (t)).
この拡散変調波I)ssは出力端子軸1を介して、例え
はアンテナ(図示せず)より送信される。This spread modulated wave I)ss is transmitted via the output terminal shaft 1, for example from an antenna (not shown).
なお、LPFIIの遮断周波数は、クロ・ンクノ(ルス
5c(t)の1ビット時間長をTOとした場合、1 /
T oの値に設定される。これは、拡散符号発生回路
9にて生成されるSS信号のメインローブの上端の周波
数に相当するもので、例えばTO=1μsecの場合に
はl HN3となる。なお、復調部のLPFl2の通過
特性もこのLPFIIと同じであるが、LPFl 3は
、はぼ情報信号りの周波数帯域のみを通過させる特性を
有している。Note that the cutoff frequency of LPFII is 1 / when the 1-bit time length of clock pulse 5c (t) is taken as TO.
It is set to the value of T o. This corresponds to the frequency of the upper end of the main lobe of the SS signal generated by the spreading code generation circuit 9, and becomes lHN3 when TO=1 μsec, for example. Note that the pass characteristics of the LPF I2 in the demodulation section are also the same as those of the LPF II, but the LPF I 3 has a characteristic of passing only the frequency band of the information signal.
次に、復調部の構成及び機能、動作について説明する。Next, the configuration, function, and operation of the demodulation section will be explained.
例えばアンテナ(図示せず)により受信。For example, received by an antenna (not shown).
検波され、LPFl2にてメインローブ以外の不要な高
域成分を除去された信号は、本来第6図(C)と同じ拡
散変調波I)ssのみの筈であるが、伝送媒体21を通
過中に様々なノイズが混入することが多く、時には第6
図(0)に示されるような、かなり大レベルの干渉波(
妨害波)Uが混入する場合もある。従って、乗算器3に
おいて、拡散符号発生回路9からの拡散符号信号P(変
調部の拡散符号発生回路8の拡散符号信号と同期してい
る)によって逆拡散すると、逆拡散信号eには、同図(
E)図示の如く、所望の復調情報信号りの他に、拡散さ
れた妨害波(SS干渉波)Uss等が含まれてくる。そ
こで、狭帯域特性(例えば遮断周波数fc15KH2)
のLPF 13を通すことにより、復調情報信号(情報
データ)D以外の不要な高域成分を除去しているが、S
S干渉波の低域成分u#JLPF13を通過するので、
これによりDN比の向上に限界が生じてしまう(同図(
F)参照)。The signal that has been detected and from which unnecessary high-frequency components other than the main lobe have been removed by LPF12 is originally supposed to be only the spread modulation wave I)ss as shown in FIG. 6(C), but it is currently passing through the transmission medium 21. Various noises are often mixed into the
As shown in Figure (0), there is a fairly large level of interference wave (
Interfering waves) U may also be mixed in. Therefore, when despreading is performed in the multiplier 3 using the spreading code signal P from the spreading code generating circuit 9 (synchronized with the spreading code signal of the spreading code generating circuit 8 of the modulation section), the despreading signal e has the same figure(
E) As shown in the figure, in addition to the desired demodulated information signal, spread interference waves (SS interference waves) Uss, etc. are included. Therefore, narrowband characteristics (for example, cutoff frequency fc15KH2)
By passing the S
Since the low frequency component of the S interference wave passes through u#JLPF13,
This puts a limit on the improvement of the DN ratio (see figure (
See F).
かかるSS干渉波成分やノイズ成分を更に抑圧しようと
する従来技術として、例えば第7図(A)に示すような
回路もある。これは、上記第6図(E)の如き逆拡散信
号eを、SS復調器(SS DFM)42にて再び乗算
して干渉波成分Uを復元し、狭帯域ろ波器(N、B B
PF) 43によりSN比を高めてから、拡散変調器(
SS N0D)44にて再び拡散変調してSS干渉波を
再生し、減算器46の負入力端子に供給する。一方、遅
延回路41等により入力信号の位相と振幅を再生SS干
渉波に合せた後、減算器46の正入力端子に供給し、入
力信号からSS干渉波を減算することにより、干渉波の
抑圧を行なっている(SS干渉信号再生型〉。As a conventional technique for further suppressing such SS interference wave components and noise components, there is also a circuit as shown in FIG. 7(A), for example. This is done by multiplying the despread signal e as shown in FIG. 6(E) again in the SS demodulator (SS DFM) 42 to restore the interference wave component U, and then using the narrowband filter (N, B B
After increasing the S/N ratio using PF) 43, a spreading modulator (
SS N0D) 44 performs spread modulation again to reproduce the SS interference wave, and supplies it to the negative input terminal of a subtracter 46. On the other hand, after adjusting the phase and amplitude of the input signal to the reproduced SS interference wave using the delay circuit 41 etc., the input signal is supplied to the positive input terminal of the subtracter 46 and the SS interference wave is subtracted from the input signal, thereby suppressing the interference wave. (SS interference signal regeneration type).
なお、−波器43の代りに、第7図(B)に示すような
狭帯域消去フィルタ(N、B BEF) 45を使用し
て、逆拡散復側器42による拡散復調後にSS復調信号
を除去し、その信号を再び拡散変調して所望の信号を再
生する方式(SS復調信号除去型)もある。Note that, instead of the negative filter 43, a narrow band elimination filter (N,B BEF) 45 as shown in FIG. There is also a method (SS demodulation signal removal type) in which the signal is removed and the signal is spread-modulated again to reproduce a desired signal.
かかる従来のSS通信方式の復調部における逆拡散(干
渉波抑圧)特性(ノイズリダクション特性)を、第4図
の曲線(イ)に示す。The despreading (interference wave suppression) characteristics (noise reduction characteristics) in the demodulation section of such a conventional SS communication system are shown in the curve (A) of FIG.
かかる従来のSS通信方式やSS干渉波除去方式には、
次のような問題点がある。Such conventional SS communication methods and SS interference wave removal methods include
There are the following problems.
(1)復調された情報信号の中に、第6図([)にも見
られたようなノイズ成分が残ってしまう。(1) Noise components as seen in FIG. 6 ([) remain in the demodulated information signal.
2第5図、第7図示の従来方式のものは、既知のSS干
渉波に限って有効であり、ランダムノイズや未知のSS
干渉波には殆ど対処できない。2 The conventional methods shown in Figures 5 and 7 are effective only for known SS interference waves, and are effective against random noise and unknown SS interference waves.
It can hardly deal with interference waves.
3複数の既知のSS干渉波に対処しようとすると、複数
の逆拡散復調器、互いに通過帯域が異なる複数の狭帯域
ろ波器、複数の拡散変調器によるループ、及び加算器が
必要となり、構成がかなり複雑となって、コストも上昇
する。3 In order to deal with multiple known SS interference waves, multiple despreading demodulators, multiple narrowband filters with mutually different passbands, loops with multiple spreading modulators, and adders are required. becomes quite complex and increases costs.
二課題を解決するための手段〕
本発明のスペクトル拡散変調復調方式は、変調部と復調
部の双方に等価な拡散符号を生成し出力する第1.第2
の拡散符号発生回路を夫々備え、変調部には入力情報信
号を該第1の拡散符号発生回路からの拡散符号を乗算す
ることにより拡散変調してスペクトル拡散信号を出力す
る拡散手段を備え、復調部には、任意の伝送手段又は記
録再生媒体を介して得られたスペクトル拡散信号を第2
の拡散符号発生回路からの拡散符号により逆拡散を行な
う逆拡散回路部を備えて、夫々変調及び復調を行なうよ
うにしたものであり、特に、上記逆拡散回路部を、任意
の伝送手段又は記録再生媒体を介している最中に混入し
た干渉波を含むスペクトル拡散信号に第2の拡散符号発
生回路からの拡散符号を乗算することにより逆拡散を行
なう第1の乗算器と、この乗算器により逆拡散された信
号中より復調情報信号を含む干渉波の低域成分を除去す
る第1の高域F波器と、この高域−波器の出力に拡散符
号を乗算することにより干渉波を復調する第2の乗算器
と、上記スペクトル拡散信号のメインローブかエネルギ
ー的に略半分となる箇所の周波数と同じ値の遮断周波数
を有する第1の低域−波器と、この低域ろ波器を通過し
た第2の乗算器出力に拡散符号を乗算することにより干
渉波を再度拡散する第3の乗算器と、この乗算器により
拡散された干渉波のスペクトルを第1の乗算器出力の干
渉波スペクトルと等しくなるよう補償する第1のイコラ
イザと、このイコライザの出力と第1の乗算器出力との
減算を行なうことにより。Means for Solving Two Problems] The spread spectrum modulation demodulation method of the present invention has a first method that generates and outputs an equivalent spreading code to both a modulator and a demodulator. Second
The modulation unit includes a spreading means for multiplying the input information signal by the spreading code from the first spreading code generating circuit to perform spread modulation and output a spread spectrum signal, The second part includes a second spread spectrum signal obtained via any transmission means or recording/reproducing medium.
The despreading circuit section is provided with a despreading circuit section that performs despreading using a spreading code from a spreading code generation circuit, and performs modulation and demodulation, respectively.In particular, the despreading circuit section can be connected to any transmission means or recording device. A first multiplier that performs despreading by multiplying a spread spectrum signal containing interference waves mixed in while passing through a reproduction medium by a spreading code from a second spreading code generation circuit; A first high-frequency F-wave device removes the low-frequency components of the interference wave including the demodulated information signal from the despread signal; a second multiplier for demodulating; a first low-frequency filter having a cut-off frequency equal to the frequency at a point where the main lobe of the spread spectrum signal is approximately half in terms of energy; and this low-pass filter. a third multiplier that spreads the interference wave again by multiplying the output of the second multiplier that has passed through the multiplier by a spreading code; By providing a first equalizer that compensates to be equal to the interference wave spectrum and subtracting the output of this equalizer and the output of the first multiplier.
低域の干渉波成分が除去された信号を出力する第1の減
算器と、この減算器の出力信号のうち復調情報信号を含
む干渉波の低域成分を除去する第2の高域ろ波器と、こ
の高域ろ波器の出力に拡散符号を乗算することにより干
渉波を復調する第4の乗算器と、上記第1の低域ろ波器
と同じ値の遮断周波数を有する第3の高域ろ波器と、こ
の高域ろ波器を通過した第4の乗算器出力に拡散符号を
乗算することにより干渉波を再度拡散する第5の乗算器
と、この乗算器により拡散された干渉波のスペクトルを
第1の減算器出力の干渉波スペクトルと等しくなるよう
補償する第2のイコライザと、このイコライザの出力と
第1の減算器出力との減算を行なうことにより、高域の
干渉波成分が除去された信号を出力する第2の減算器と
を備えて、夫々変調及び復調を行なうことにより、上記
課題を解消したものである。a first subtracter that outputs a signal from which low-frequency interference wave components have been removed; and a second high-pass filter that removes low-frequency components of interference waves that include demodulated information signals from the output signal of this subtracter. a fourth multiplier that demodulates the interference wave by multiplying the output of the high-pass filter by a spreading code; and a third multiplier having the same cutoff frequency as the first low-pass filter. a high-pass filter; a fifth multiplier that spreads the interference wave again by multiplying the output of the fourth multiplier that has passed through the high-pass filter by a spreading code; A second equalizer compensates the spectrum of the interference wave obtained by the interference wave to be equal to the interference wave spectrum of the output of the first subtracter, and subtracts the output of this equalizer from the output of the first subtractor. The above problem is solved by providing a second subtracter that outputs a signal from which interference wave components have been removed, and performing modulation and demodulation, respectively.
本発明のスペクトル拡散変調復調方式は、比較的に低い
周波数(例えば情報信号の周波数帯域に近い周波数)を
有する干渉波のみならず、比較的に高い周波数(例えば
前記エンベロープの上端である1/Toに近い周波数)
の干渉波をも十分抑圧。The spread spectrum modulation demodulation method of the present invention not only uses interference waves having a relatively low frequency (for example, a frequency close to the frequency band of the information signal) but also a relatively high frequency (for example, 1/To which is the upper end of the envelope). (frequency close to)
sufficiently suppresses interference waves.
低減し得るものであり、以下、本発明のスペクトル拡散
変調復調方式の具体例について、図面を参照し乍ら説明
する。第1図は本発明方式を実現し得るSS変調復調装
置1の概略ブロック図であり、この図において、第5図
に示した従来装置と同一構成箇所には同一符号を付して
、その詳細な説明は省略する。なお、この変調部10と
復調部2Cとを一体的に樽成し、移動式電話等の通信装
置として使用すると一層便利である。Specific examples of the spread spectrum modulation and demodulation method of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram of an SS modulation and demodulation device 1 that can realize the method of the present invention. In this diagram, the same components as those of the conventional device shown in FIG. Further explanation will be omitted. Note that it is more convenient to form the modulator 10 and the demodulator 2C into one body and use it as a communication device such as a mobile phone.
復調部20は、LPF12及び拡散符号発生口#I9の
他に逆拡散回路部26等を備え、これらを第1図示の如
く接続して構成される。拡散符号発生回路9は変調部1
0側の拡散符号発生回路8と同等のタロツクパルスS。The demodulation section 20 includes a despreading circuit section 26 and the like in addition to the LPF 12 and the spreading code generation port #I9, and is configured by connecting these sections as shown in the first diagram. Spreading code generation circuit 9 is modulating section 1
Tarock pulse S equivalent to the spreading code generation circuit 8 on the 0 side.
(1)を入力し、これを基に等価な拡散符号P(tH通
常は擬似雑音符号)を生成するよう設計されている。な
お、変調部10と復調部20の間に介在する伝送・記録
再生の媒体(以下単に「伝送媒体」とも記述する)30
は、本発明方式を通信装置に適用した場合には空中とな
り、記録再生装置に応用した場合には、装置を構成1−
る諸回路や磁気テープ等の記録媒体となる。It is designed to input (1) and generate an equivalent spreading code P (tH usually a pseudo-noise code) based on this. Note that a transmission/recording/reproduction medium (hereinafter also simply referred to as "transmission medium") 30 is interposed between the modulation section 10 and the demodulation section 20.
is in the air when the method of the present invention is applied to a communication device, and when it is applied to a recording/reproducing device, the device has configuration 1-
It becomes a recording medium such as various circuits and magnetic tape.
第2図は逆拡散回路部26の一実施例の具体的構成を示
すブロック図である。この図に示すように、逆拡散回路
部26は、乗算器3〜7.低域ろ波器(LPF)13,
14;高域ろ波器(HPF)21〜23.減算器17.
19及びフェイズシフタ(pS)27.28等を偶え、
これらを同図示の如く接続して構成される。HPF21
(Fs)は乗算器3の出力信号中の復調情報信号りを除
去するために、情報信号りの周波数帯域の上端よりも少
し高い値にその遮断周波数チ。I(例えば5 kHz)
を設定される。また、LPF14とHPF23とは互い
に相補的な通過特性を有し、それらの遮断周波数fc2
は、クロックパルスS。(1)の1ビット時間長をTO
とした場合、
チ。2崎1 / 3 T o ・・・・・・・・・・
・・・・・・・・・・・(2)の値に設定される。これ
は、拡散符号発生回路9゜8にて生成されるスペクトル
拡散信号のメインローブがエネルギー的に略2分される
箇所の周波数に相当するものであり、例えば、To=1
μsec< 1/T o = I MHz)の場合、チ
c2”=310にHzとなる。FIG. 2 is a block diagram showing a specific configuration of one embodiment of the despreading circuit section 26. As shown in FIG. As shown in this figure, the despreading circuit unit 26 includes multipliers 3 to 7. Low pass filter (LPF) 13,
14; High-pass filter (HPF) 21-23. Subtractor 17.
19 and phase shifter (pS) 27.28 etc.,
These components are connected as shown in the figure. HPF21
(Fs) is set to a value slightly higher than the upper end of the frequency band of the information signal in order to remove the demodulated information signal in the output signal of the multiplier 3. I (e.g. 5 kHz)
is set. Furthermore, the LPF 14 and the HPF 23 have mutually complementary passing characteristics, and their cutoff frequency fc2
is the clock pulse S. The 1-bit time length of (1) is TO
If , then Ch. 2 Saki 1/3 T o・・・・・・・・・・・・
・・・・・・・・・・・・It is set to the value of (2). This corresponds to the frequency at which the main lobe of the spread spectrum signal generated by the spreading code generation circuit 9°8 is approximately divided into two in terms of energy. For example, To=1
If μsec<1/T o = I MHz), then chic2''=310 Hz.
また、HPF22の遮断周波数fC3は、HPF21の
遮断周波数/”CIよりも、後述する理由により若干高
く設定されている。更に、イコライザ31及び32は、
その原理的特性が第8図(A)、 (B)に夫々示され
るよう構成されている。即ち、イコライザ31では周波
数f a(=fcl / 2 )以下の帯域成分を6d
Bアツプさせて、周波数fc+以上の帯域成分に比べて
ゲインを2倍にするよう構成されており、イコライザ3
2は周波数fb(”チC3/4)以下の帯域成分を12
dBアツプさせて、周波数fc3以上の帯域成分に比べ
てゲインを4倍にするよう構成されている。Further, the cutoff frequency fC3 of the HPF 22 is set slightly higher than the cutoff frequency/"CI of the HPF 21 for reasons described later.Furthermore, the equalizers 31 and 32 are
It is constructed so that its principle characteristics are shown in FIGS. 8(A) and 8(B), respectively. That is, the equalizer 31 divides the band components below the frequency f a (=fcl/2) by 6d.
The equalizer 3
2 is the band component below the frequency fb ("chi C3/4)"
It is configured to increase the gain by dB and quadruple the gain compared to the band components of frequencies fc3 and above.
以下、このSS変調復調装置(以下単に1装置」とも記
載する)1の具体的な動作について、本装置1を通信機
器に適用するものとして、第1図乃至第3図(各構成部
分の出力信号のスペクトル図)等を併せ参照し乍ら説明
する。この場合、伝送媒体30は特に構成されるもので
はなく、両アンテナ間の空中となる。なお、送信側(変
調部10)の構成及び動作は、第5図(A)に示した従
来装置と同じなので、その詳細な説明を省略する。Hereinafter, the specific operation of this SS modulation and demodulation device (hereinafter also simply referred to as "one device") 1 will be explained as follows, assuming that this device 1 is applied to communication equipment. This will be explained with reference to the signal spectrum diagram) and the like. In this case, the transmission medium 30 is not particularly configured and is in the air between both antennas. Note that the configuration and operation of the transmitting side (modulating section 10) are the same as those of the conventional device shown in FIG. 5(A), so a detailed explanation thereof will be omitted.
受信側(復調部20)において、アンテナ(図示せず)
により受信、検波され、更にLPFIIにて拡散符号の
サイドローブを除去されてた信号は、本来前記第6図(
C)と同じく拡散変調波信号I)ssのみの筈であるが
、伝送媒体30の通過中に様々なノイズか混入すること
が多く、時には第3図(A)に示されるような、かなり
大レベルの干渉波(妨害波)UI#U2等が混入する場
合もある。On the receiving side (demodulator 20), an antenna (not shown)
The signal that was received and detected by LPFII and had the sidelobes of the spreading code removed by LPFII was originally shown in Fig. 6 (
Similar to C), the spread modulated wave signal I) is supposed to be only ss, but various noises are often mixed in while passing through the transmission medium 30, and sometimes quite large noises as shown in Fig. 3(A) are generated. Interference waves (disturbance waves) such as UI#U2 may also be mixed in.
本発明方式における逆拡散回路部26は、高低いずれの
周波数(帯域)を有する2つ以上の干渉波についても、
従来装置以上の大幅な抑圧機能を発揮し得るものであり
、以下、干渉波の代表例として、情報信号りの周波数帯
域に近い低域周波数を有する干渉波U、と、エンベロー
プの上端17TOに近い周波数の干渉波U2を例にとっ
て説明する。The despreading circuit section 26 in the method of the present invention is configured to handle two or more interference waves having both high and low frequencies (bands).
This device can exhibit a greater suppression function than conventional devices.Hereafter, as representative examples of interference waves, interference waves U having a low frequency close to the frequency band of the information signal, and interference wave U having a low frequency close to the frequency band of the information signal, and interference waves close to the upper end of the envelope 17TO are used. This will be explained by taking the frequency interference wave U2 as an example.
まず、SS変調信号Dssに干渉波trl及びU2が混
入した信号a(第3図(A)参照)を乗算器3に供給し
て、ここで入力端子In5(P N G 9 )からの
拡散符号P(P(t))を乗算すると、同図(B)に示
されるように、SS変調信信号)ssは逆拡散されて情
報信号りか復調すると共に、干渉波U I # U 2
は乗算(拡散)されて夫々SS干渉波(拡散妨害波)U
+as 、U2S5となる。これらの信号成分より成る
乗算(逆拡散)出力信号すを、第1のHPF(高域ろ波
器>21(Fl)に供給して、復調情報信号りを含む遮
断周波数チc1以下の周波数成分を除去すると、SS干
渉波U Is S及びU 2S 5の一部も除去されて
、夫々U+’ss、 U2’ssとなる(同図(C)参
照)。ここで、信号Ul’SSは、両遮断周波数−チc
1〜チc1間にスペクトル成分を有する仮想信号u+(
=U+’5s−Utss 、図示せず)とSS干渉波U
ssの合成波と見做すことができ、従ってこの信号Ul
’SSに、乗算器4において拡散符号Pを乗算すると、
SS干渉波u ts sが逆拡散された信号U、と、仮
想信号’ulが拡散された信号11が生じる。また、信
号U2’S!liの方も同様な原理により、乗算器4に
おける乗算の結果、復調干渉波U2と復調されない洩れ
成分12が生じる(同図fD)参照)、この洩れ成分1
2が11よりレベル的に低いのは、同図(C)に示した
ように、HPF21で除去される箇所のSS干渉波U2
’SSのエネルギーがU+’ssより小さいためである
。なお、洩れ成分1+、12は位相が逆転しているので
、第3図fOL (EL (J)、 (に)では破線で
示している。First, the signal a (see FIG. 3(A)) in which the SS modulated signal Dss is mixed with the interference wave trl and U2 is supplied to the multiplier 3, where the spreading code from the input terminal In5 (PNG 9 ) is When multiplied by P(P(t)), the SS modulated signal) ss is despread and demodulated as an information signal, as shown in FIG.
are multiplied (spread) to produce each SS interference wave (spread interference wave) U
+as, U2S5. A multiplication (despreading) output signal consisting of these signal components is supplied to a first HPF (high-pass filter > 21 (Fl)) to extract frequency components below the cutoff frequency chic1 including the demodulation information signal. When is removed, part of the SS interference waves U Is S and U 2S 5 are also removed, resulting in U+'ss and U2'ss, respectively (see (C) in the same figure). Here, the signal U I'SS is Both cutoff frequencies-ch c
A virtual signal u+(
=U+'5s-Utss, not shown) and SS interference wave U
It can be regarded as a composite wave of ss, and therefore this signal Ul
'When SS is multiplied by the spreading code P in the multiplier 4,
A signal U, which is obtained by despreading the SS interference wave u ts s, and a signal 11, which is obtained by spreading the virtual signal 'ul, are generated. Also, signal U2'S! As for li, due to the same principle, as a result of multiplication in the multiplier 4, a demodulated interference wave U2 and a leakage component 12 that is not demodulated are generated (see fD in the same figure), and this leakage component 1
The reason why 2 is lower in level than 11 is because of the SS interference wave U2 removed by the HPF 21, as shown in the same figure (C).
This is because the energy of 'SS is smaller than U+'ss. In addition, since the phases of the leakage components 1+ and 12 are reversed, they are shown by broken lines in FIG.
次に、乗算出力信号dを、同図(E)に示すようにLP
F14にて絶対値が遮断周波数t。2以上の帯域成分を
除去して、高域の干渉波U2等の無い信号eを得、これ
を乗算器5に供給して拡散符号Pを乗算すると、同図(
F)のようなスペクトルの信号qが得られる。この信号
qのうちL2は、LPF14によってエネルギーを半減
された洩れ成分12′(位相的には負なので破線で示し
ている)が復調されたものであり、これは同図(C)に
おいてSS干渉波U2’SSの除去された部分(遮断周
波数−fcl〜fc1間)のレベル半減のスペクトルに
相当する。同様に半減された洩れ成分11′(位相的に
は負)の方も復調されて、同図(B)に示しなSS干渉
波U +s sのうち遮断周波数−fcl〜fc1間の
エネルギーを略半減させるので、干渉波U1の拡散スペ
クトルはU +S S″となる。Next, the multiplication output signal d is converted to LP as shown in FIG.
At F14, the absolute value is the cutoff frequency t. 2 or more band components are removed to obtain a signal e free of high-frequency interference waves U2, etc., and this is supplied to the multiplier 5 and multiplied by the spreading code P.
A signal q with a spectrum like F) is obtained. Of this signal q, L2 is the demodulated leakage component 12' (indicated by a broken line because it is negative in phase) whose energy has been halved by the LPF 14, and this is the result of the SS interference in FIG. This corresponds to the spectrum of the removed portion of the wave U2'SS (between the cutoff frequency -fcl and fc1) whose level is halved. Similarly, the halved leakage component 11' (negative in terms of phase) is demodulated, and the energy between the cutoff frequency -fcl and fc1 of the SS interference wave U+ss shown in FIG. Since it is reduced by half, the spread spectrum of the interference wave U1 becomes U + S S''.
以上のような原理で生成される信号qをイコライザ31
に供給すると、第8図FA)に示した動作特性によって
絶対値で周波数fa以下の帯域成分が補償(2倍に増強
)され、第3図[G)に示すように、SS干渉波U +
s sか復元される。そこで、減算器17において、上
記乗算器3の出力信号すとの減算を行なうと、SS干渉
波U +s sの方は消滅し、同図fH)に示すように
、情報信号りと干渉波U2の拡散スペクトル成分U2S
S+2L2が通過する。即ち、減算器17までの信号処
理によって、低域スペクトルを有する干渉波やノイズを
抑圧、除去しているわけである。The signal q generated according to the above principle is transmitted to the equalizer 31.
, the band components below the frequency fa are compensated for (doubled) in absolute value by the operating characteristics shown in FIG.
s s is restored. Therefore, when the subtracter 17 subtracts the output signal S of the multiplier 3, the SS interference wave U The spread spectrum component U2S of
S+2L2 passes. That is, the signal processing up to the subtracter 17 suppresses and removes interference waves and noise having a low frequency spectrum.
続いて、上記情報信号りとSS干渉波(U 28 S+
2L2)よりなる信号りをHPF22に供給して、SS
干渉波のうち2L2の部分と情報信号りとを除去する。Next, the above information signal and SS interference wave (U 28 S+
2L2) is supplied to the HPF22, and the SS
The 2L2 part and the information signal are removed from the interference wave.
その目的のため、HPF22の遮断周波数チc3はHP
F21の遮断周波数fc+より若干高くなっているが、
これはSS干渉波の2L2成分に関与したイコライザ3
1の特性に拘るものであり、動作原理や作用はHPF2
1と大差ない。For that purpose, the cutoff frequency chi c3 of HPF22 is
Although it is slightly higher than the cutoff frequency fc+ of F21,
This is the equalizer 3 that is involved in the 2L2 component of the SS interference wave.
It is based on the characteristics of HPF 1, and the operating principle and action are similar to HPF 2.
Not much different from 1.
従って、HPF21の出力信号iの波形も、第3図(C
)同様tJ2’ssと記している。Therefore, the waveform of the output signal i of the HPF 21 also changes as shown in FIG.
) Similarly, it is written as tJ2'ss.
かかる信号iを次段の乗算器6に供給して拡散符号Pを
乗算すると、前記乗算器4での信号処理と同様に、復調
(逆拡散)された干渉波U2と復調されない洩れ成分1
2とよりなる信号jが生じる。この信号jをHPF24
に通して、絶対値で遮断周波数チc2以下の帯域成分を
除去した後、乗算器7に供給して拡散符号Pを乗算する
と、前記乗算器5での信号処理とほぼ同様に、干渉波成
分が拡散されるが、エネルギーを半減された洩れ成分1
2′のために、遮断周波数fc+以下のレベルが略半減
したスペクトルのSS干渉波U 2s s ”(信号i
)となる(第3図(E)参照)。かかる乗算器出力lを
イコライザ32に供給すると、第8図(B)に示した動
作特性によって周波数fb以下の帯域成分が補償(4倍
に増強)され、第3図(H)に示すようなスペクトルの
SS干渉波U2SS”’(信号m)となる、この信号m
は、同図(H)に示した信号成分1j 23 S÷2L
2とほぼ同じスペクトルなので、両信号を減算器19に
供給して減算を行なうとSS干渉波成分は消滅し、上記
減算器17の出力信号りのうちの情報信号りのみが出力
される(同図(H)参照)。即ち、減算器17の出力側
から減算器1つまでの信号処理によって、高域スペクト
ルを有する干渉波やノイズを抑圧、除去しているわけで
ある。When this signal i is supplied to the next-stage multiplier 6 and multiplied by the spreading code P, similar to the signal processing in the multiplier 4, demodulated (despread) interference wave U2 and undemodulated leakage component 1 are generated.
A signal j consisting of 2 is generated. This signal j is passed through HPF24
After removing the band components below the cutoff frequency C2 in absolute value, the signal is supplied to the multiplier 7 and multiplied by the spreading code P. In almost the same way as the signal processing in the multiplier 5, the interference wave component is is diffused, but leakage component 1 whose energy is halved
2′, the SS interference wave U 2s s ” (signal i
) (see Figure 3(E)). When such a multiplier output l is supplied to the equalizer 32, the band components below the frequency fb are compensated for (four times enhanced) according to the operating characteristics shown in FIG. 8(B), and the result is as shown in FIG. 3(H). This signal m becomes the spectrum SS interference wave U2SS'' (signal m)
is the signal component 1j 23 S÷2L shown in the same figure (H)
Since the spectrum is almost the same as that of 2, when both signals are supplied to the subtracter 19 and subtracted, the SS interference wave component disappears, and only the information signal among the output signals of the subtracter 17 is output (the same (See figure (H)). That is, interference waves and noise having a high frequency spectrum are suppressed and removed by signal processing from the output side of the subtracter 17 to one subtracter.
なお、LPF13(遮断周波数−チc+)は必すしも無
くてもよいか、減算器19以前の諸口路で生じた細かな
洩れノイズを一層確実に除去できるので、DN比の一段
と優れた情報信号りを出力端子0ut2に得ることがで
きる。It should be noted that the LPF 13 (cutoff frequency −chi c+) may not be necessary or may be omitted, since it can more reliably remove small leakage noises generated in the various ports before the subtracter 19, so that the information signal with an even better DN ratio can be obtained. can be obtained at the output terminal 0ut2.
逆拡散回路部26(復調部20)における干渉波抑圧特
性を、第4図の曲線(ロ)に示す。この図から、本発明
方式においては、従来方式よりも一段と抑圧特性が改善
され、特にスペクトル拡散信号のメインローブの両端付
近の周波数帯域では大幅に低減し得る特性となっている
。The interference wave suppression characteristic in the despreading circuit section 26 (demodulating section 20) is shown by the curve (b) in FIG. From this figure, it can be seen that in the method of the present invention, the suppression characteristics are further improved than in the conventional method, and in particular, the suppression characteristics can be significantly reduced in the frequency band near both ends of the main lobe of the spread spectrum signal.
以上の説明においては、高い周波数を有する干渉波より
も低い周波数の干渉波の方を先に抑圧除去するよう構成
した例を挙げたが、逆に高い周波数を有する干渉波の方
を先に除去するよう構成しても良い。また、入力端子I
^1に供給される入力信号は情報信号りとしたが、これ
に限らず他の信号(例えばFM変調やPSに変調された
データ)でも良い。更に、本発明のSS変調復調方式を
通信機器に適用するものとして説明したが、これに限ら
ず、例えば記録再生装置に応用しても良い。In the above explanation, an example was given in which the interference waves with a lower frequency are suppressed and removed earlier than the interference waves with a higher frequency, but conversely, the interference waves with a higher frequency are removed first. It may be configured to do so. In addition, input terminal I
Although the input signal supplied to ^1 is an information signal, it is not limited to this, and may be other signals (for example, FM modulation or PS modulated data). Furthermore, although the SS modulation and demodulation method of the present invention has been described as being applied to communication equipment, the present invention is not limited to this, and may be applied to, for example, a recording/reproducing apparatus.
本発明のスペクトル拡散変調復調方式は以上のように構
成したので、従来方式に比べてかなり構成が簡潔になり
、かなり大レベルの低域及び/又は高域周波数(帯域)
の干渉波が混入してもこれを大幅に抑圧、除去でき、C
W傷信号単一波)やランダムノイズ等に対してもかなり
抑圧効果があり、更に、中域程度の周波数(スペクトル
拡散信号のメインローブがエネルギー的に略半分となる
箇所の周波数)の干渉波が混入してもこれを良好に除去
できるという優れた特徴を有している。Since the spread spectrum modulation demodulation method of the present invention is configured as described above, the configuration is considerably simpler than that of the conventional method, and it can handle a considerably large level of low and/or high frequency (band).
Even if interference waves of
It has a considerable suppressing effect on W damage signal (single wave) and random noise, and it also suppresses interference waves in the mid-range frequency (the frequency at which the main lobe of the spread spectrum signal is approximately half in terms of energy). It has the excellent feature of being able to remove contaminants well even if they are mixed in.
第1図は本発明のSS変調復調方式の構成例を示す概略
ブロック図、第2図は本発明方式を実現する装置の主要
部である逆拡散回路部の一実施例を示すブロック図、第
3図(^)〜fN)は逆拡散回路部の各構成部分の動作
説明用スペクトル図、第4図は各方式の復調部(逆拡散
回路部〉における干渉波抑圧特性図、第5図(A)、
(B)及び第7図(A)(B)は従来方式説明用ブロッ
ク構成図、第6図(^)〜fF)は従来方式の動作説明
用周波数スペクトル図、第8図(^)、 FB)は上記
逆拡散回路部を構成する各イコライザの原理的動作特性
図である。
1・・・SS変調復調装置、2〜7・・・乗算器、8゜
9・・・拡散符号発生口路、10・・・変調部、11〜
14・・・LPF (低域ろ波器)、17.19・・・
減算器、20・・・復調部、21〜23・・・HPF
(高域ろ波器)、26・・・逆拡散回路部、30・・・
伝送・記録再生の媒体、31.32・・・イコライザ、
In+〜In6・・・入力端子、漏1〜−2・・・出力
端子。
特許出願人 日本ビクター株式会社
代表者 埋木 邦夫
手続補正書く方式)
平成3年8月2ら
特許片長! 殿
■、事件の表示
平成1年特許願第314598号
2、発明の名称
スペクトル拡散変調復調方式
3、補正をする者
事件との関係 特許出願人
住所 神奈川県横浜市神奈用区守屋町3丁目12番地4
、補正命令の日付
平成3年5月14日(発送臼)
5、補正の対象
明細書の図面の簡単な説明の桐
6、補正の内容
明細書第24頁第7行の「第5図(A)CB)
」を「第5図」FIG. 1 is a schematic block diagram showing a configuration example of the SS modulation and demodulation method of the present invention, FIG. Figure 3 (^) to fN) is a spectrum diagram for explaining the operation of each component of the despreading circuit section, Figure 4 is an interference wave suppression characteristic diagram in the demodulation section (despreading circuit section) of each method, and Figure 5 ( A),
(B) and FIGS. 7(A) and (B) are block configuration diagrams for explaining the conventional method, FIG. 6 (^) to fF) are frequency spectrum diagrams for explaining the operation of the conventional method, and FIG. 8 (^), FB ) is a diagram showing the principle operating characteristics of each equalizer constituting the despreading circuit section. DESCRIPTION OF SYMBOLS 1... SS modulation/demodulation device, 2-7... Multiplier, 8°9... Spreading code generation path, 10... Modulation section, 11-
14...LPF (low pass filter), 17.19...
Subtractor, 20... Demodulator, 21-23... HPF
(high-pass filter), 26... despreading circuit section, 30...
Transmission/recording/reproduction medium, 31.32... Equalizer,
In+ to In6...input terminal, leakage 1 to -2...output terminal. Patent applicant Kunio Umiki, representative of Victor Japan Co., Ltd. Procedure amendment writing method) August 2, 1991 Patent length! Tono ■, Display of the case 1999 Patent Application No. 314598 2, Name of the invention Spread spectrum modulation demodulation method 3, Person making the amendment Relationship to the case Patent applicant address 3-12 Moriya-cho, Kanayō-ku, Yokohama-shi, Kanagawa Prefecture Address 4
, Date of the amendment order: May 14, 1991 (dispatch mill) 5. Paulownia 6 of the brief explanation of the drawing of the specification subject to the amendment, ``Figure 5 ( A) CB)” to “Figure 5”
Claims (1)
する第1,第2の拡散符号発生回路を夫々有し、上記変
調部には入力情報信号を該第1の拡散符号発生回路から
の拡散符号を乗算することにより拡散変調してスペクト
ル拡散信号を出力する拡散手段を備え、上記復調部には
、任意の伝送手段又は記録再生媒体を介して得られたス
ペクトル拡散信号を上記第2の拡散符号発生回路からの
拡散符号により逆拡散を行なう逆拡散回路部を備えて、
夫々変調及び復調を行なうスペクトル拡散変調復調方式
であって、 上記逆拡散回路部を、任意の伝送手段又は記録再生媒体
を介している最中に混入した干渉波を含むスペクトル拡
散信号に上記第2の拡散符号発生回路からの拡散符号を
乗算することにより逆拡散を行なう第1の乗算器と、こ
の乗算器により逆拡散された信号中より復調情報信号を
含む干渉波の低域成分を除去する第1の高域ろ波器と、
この高域ろ波器の出力に上記拡散符号を乗算することに
より干渉波を復調する第2の乗算器と、上記スペクトル
拡散信号のメインローブがエネルギー的に略半分となる
箇所の周波数と同じ値の遮断周波数を有する第1の低域
ろ波器と、この低域ろ波器を通過した上記第2の乗算器
出力に上記拡散符号を乗算することにより干渉波を再度
拡散する第3の乗算器と、この乗算器により拡散された
干渉波のスペクトルを上記第1の乗算器出力の干渉波ス
ぺクトルと等しくなるよう補償する第1のイコライザと
、このイコライザの出力と上記第1の乗算器出力との減
算を行なうことにより、低域の干渉波成分が除去された
信号を出力する第1の減算器と、この減算器の出力信号
のうち復調情報信号を含む干渉波の低域成分を除去する
第2の高域ろ波器と、この高域ろ波器の出力に上記拡散
符号を乗算することにより干渉波を復調する第4の乗算
器と、上記第1の低域ろ波器と同じ値の遮断周波数を有
する第3の高域ろ波器と、この高域ろ波器を通過した上
記第4の乗算器出力に上記拡散符号を乗算することによ
り干渉波を再度拡散する第5の乗算器と、この乗算器に
より拡散された干渉波のスペクトルを上記第1の減算器
出力の干渉波スペクトルと等しくなるよう補償する第2
のイコライザと、このイコライザの出力と上記第1の減
算器出力との減算を行なうことにより,高域の干渉波成
分が除去された信号を出力する第2の減算器とを備えて
、夫々変調及び復調を行なうことを特徴とするスペクト
ル拡散変調復調方式。[Scope of Claims] Both the modulating section and the demodulating section have first and second spreading code generation circuits that generate and output equivalent spreading codes, and the modulating section receives the input information signal from the first spreading code. The demodulating section includes a spreading means for outputting a spread spectrum signal by performing spread modulation by multiplying a spreading code from a spreading code generating circuit of the comprising a despreading circuit section that despreads the spread signal using a spreading code from the second spreading code generating circuit;
A spread spectrum modulation demodulation method that performs modulation and demodulation, respectively, in which the despreading circuit section is applied to the second spread spectrum signal containing interference waves mixed in while passing through an arbitrary transmission means or recording/reproducing medium. a first multiplier that performs despreading by multiplying by a spreading code from a spreading code generation circuit; and a first multiplier that removes low frequency components of interference waves including demodulated information signals from the signal despread by this multiplier. a first high-pass filter;
A second multiplier demodulates the interference wave by multiplying the output of the high-pass filter by the spreading code, and the frequency is the same as the frequency at the point where the main lobe of the spread spectrum signal is approximately halved in terms of energy. a first low-pass filter having a cut-off frequency of a first equalizer for compensating the spectrum of the interference wave spread by the multiplier to be equal to the interference wave spectrum of the output of the first multiplier; and a first equalizer for multiplying the output of the equalizer by the first multiplier. a first subtractor that outputs a signal from which low-frequency interference wave components have been removed by subtracting the low-frequency interference wave component from the output of the subtractor; a second high-pass filter that removes the interference wave; a fourth multiplier that demodulates the interference wave by multiplying the output of the high-pass filter by the spreading code; and the first low-pass filter. The interference wave is spread again by multiplying the output of the fourth multiplier that has passed through the third high-pass filter and the fourth multiplier that has passed through the third high-pass filter by the spreading code. a fifth multiplier; and a second multiplier that compensates the spectrum of the interference wave spread by the multiplier to be equal to the interference wave spectrum of the output of the first subtracter.
and a second subtracter that outputs a signal from which high-frequency interference wave components have been removed by subtracting the output of the equalizer and the output of the first subtracter. A spread spectrum modulation demodulation method characterized by performing demodulation.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1314598A JPH04828A (en) | 1989-12-04 | 1989-12-04 | Spread spectrum modulating/demodulating system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1314598A JPH04828A (en) | 1989-12-04 | 1989-12-04 | Spread spectrum modulating/demodulating system |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH04828A true JPH04828A (en) | 1992-01-06 |
Family
ID=18055227
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1314598A Pending JPH04828A (en) | 1989-12-04 | 1989-12-04 | Spread spectrum modulating/demodulating system |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH04828A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009535088A (en) * | 2006-04-25 | 2009-10-01 | エスセーアー・ハイジーン・プロダクツ・アーベー | Pant-like absorber and method for making the same |
USRE42478E1 (en) | 1994-04-12 | 2011-06-21 | Sca Hygiene Products Aktiebolag | Method of manufacturing a pants-type diaper of a sanitary panty, and one such absorbent article |
US8105304B2 (en) | 2003-06-20 | 2012-01-31 | Livedo Corporation | Folded disposable pants |
-
1989
- 1989-12-04 JP JP1314598A patent/JPH04828A/en active Pending
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
USRE42478E1 (en) | 1994-04-12 | 2011-06-21 | Sca Hygiene Products Aktiebolag | Method of manufacturing a pants-type diaper of a sanitary panty, and one such absorbent article |
US8105304B2 (en) | 2003-06-20 | 2012-01-31 | Livedo Corporation | Folded disposable pants |
JP2009535088A (en) * | 2006-04-25 | 2009-10-01 | エスセーアー・ハイジーン・プロダクツ・アーベー | Pant-like absorber and method for making the same |
JP4944191B2 (en) * | 2006-04-25 | 2012-05-30 | エスセーアー・ハイジーン・プロダクツ・アーベー | Pant-like absorber and method for making the same |
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