JPH04273632A - Spread spectrum communication system - Google Patents
Spread spectrum communication systemInfo
- Publication number
- JPH04273632A JPH04273632A JP3034353A JP3435391A JPH04273632A JP H04273632 A JPH04273632 A JP H04273632A JP 3034353 A JP3034353 A JP 3034353A JP 3435391 A JP3435391 A JP 3435391A JP H04273632 A JPH04273632 A JP H04273632A
- Authority
- JP
- Japan
- Prior art keywords
- spread spectrum
- communication system
- signal
- spectrum communication
- phase
- 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.)
- Pending
Links
- 238000004891 communication Methods 0.000 title claims abstract description 18
- 238000001228 spectrum Methods 0.000 title claims abstract description 16
- 230000005540 biological transmission Effects 0.000 claims description 13
- 238000006243 chemical reaction Methods 0.000 abstract description 7
- 238000001514 detection method Methods 0.000 description 9
- 238000000034 method Methods 0.000 description 9
- 125000004122 cyclic group Chemical group 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 230000002542 deteriorative effect Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明はスペクトラム拡散通信方
式にかかわり、特にその周波数利用効率を改善する方式
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spread spectrum communication system, and more particularly to a system for improving the frequency utilization efficiency thereof.
【０００２】0002
【発明の概要】この発明はスペクトラム拡散通信方式に
おいて、伝送信号における一つの拡散符号系列の位相に
入力情報を乗せる事により、周波数利用効率を向上させ
たものである。SUMMARY OF THE INVENTION The present invention improves frequency utilization efficiency in a spread spectrum communication system by adding input information to the phase of one spreading code sequence in a transmission signal.
【０００３】0003
【従来の技術】スペクトラム拡散通信方式は任意の変調
波をその情報速度より著しく速い拡散符号によって二次
変調し周波数帯域幅を広げて伝送を行うものである。こ
の方式は対干渉波除去に特色があり、通信の秘匿、非同
期の符号多重通信方式などに利用される。2. Description of the Related Art Spread spectrum communication systems secondarily modulate an arbitrary modulated wave using a spreading code significantly faster than its information rate, thereby widening the frequency bandwidth and transmitting the wave. This method is characterized by its ability to eliminate interference waves, and is used for communication secrecy, asynchronous code multiplex communication, etc.
【０００４】このようなスペクトラム拡散通信方式の一
例をさらに詳述すると次の通りである。伝送される情報
がディジタル信号であれば一次変調波は１、０で表現さ
れる。また拡散符号としてＰＮ系列を用いた場合、伝送
される情報は一次変調波とＰＮ系列の積であり、出力は
そのＰＮ系列または極性を反転したＰＮ系列が生成され
る。受信側では入力系列の相関を取る。すなわち受信信
号を１フレーム（ＰＮ系列１周期）にわたって観測し元
のＰＮ系列と一致すれば出力１、反転であれば出力０を
与える。この検出は相関受信の技術を用いたＰＮ符号長
に等いタップ長を持つマッチトフィルタ（ＭＦ）で実現
でき、その出力には正極性または負極性のピークがフレ
ーム中に一回発生する。以上が２値のスペクトラム拡散
方式と呼ばれるものである。[0004] An example of such a spread spectrum communication system will be described in more detail as follows. If the information to be transmitted is a digital signal, the primary modulated wave is represented by 1's and 0's. Furthermore, when a PN sequence is used as a spreading code, the information to be transmitted is the product of the primary modulated wave and the PN sequence, and the output is the PN sequence or a PN sequence with the polarity inverted. On the receiving side, the correlation of the input sequence is taken. That is, the received signal is observed over one frame (one period of PN sequence), and if it matches the original PN sequence, output 1 is given, and if it is inverted, output 0 is given. This detection can be realized by a matched filter (MF) having a tap length equal to the PN code length using correlation reception technology, and a peak of positive polarity or negative polarity occurs once in a frame in its output. The above is what is called a binary spread spectrum method.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、この通
信方式においては二次変調によって伝送帯域幅が大幅に
広がるために、一般に限られた周波数帯域では伝送可能
な情報量が制限されてしまう。However, in this communication system, the transmission bandwidth is greatly expanded by secondary modulation, so the amount of information that can be transmitted is generally limited in a limited frequency band.
【０００６】そこで本発明の目的は以上のような問題を
解消し、限られた周波数帯域で、干渉除去能力や多重能
力を劣化させずに伝送容量を増大することができるスペ
クトラム拡散通信方式を提供することにある。SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems and provide a spread spectrum communication system that can increase transmission capacity in a limited frequency band without deteriorating interference removal ability or multiplexing ability. It's about doing.
【０００７】[0007]
【課題を解決するための手段】上記目的を達成するため
本発明はスペクトラム拡散通信方式において、伝送信号
における拡散符号系列の位相を入力情報に基づいて変化
させることを特徴とする。[Means for Solving the Problems] To achieve the above object, the present invention is characterized in that, in a spread spectrum communication system, the phase of a spreading code sequence in a transmission signal is changed based on input information.
【０００８】[0008]
【作用】本発明によれば、伝送信号における拡散符号系
列の位相が入力情報に基づいて変化する。これによって
、限られた周波数帯域での情報伝送量が増大する。According to the present invention, the phase of the spreading code sequence in the transmission signal changes based on input information. This increases the amount of information transmitted in a limited frequency band.
【０００９】[0009]
【実施例】まず本発明の原理について説明すると、前述
した２値のスペクトラム拡散方式に対して、本発明では
、入力信号をｎビット毎に符号化することにより、Ｎ＝
２ｎ 種類のシンボルを得る。ＰＮ系列の位相をこのＮ
種類に応じて変化させることにより、前述した２値のス
ペクトラム拡散方式と同じ帯域幅で、同方式のｎ倍の情
報を伝送する事が出来る。[Embodiment] First, the principle of the present invention will be explained. In contrast to the binary spread spectrum method described above, in the present invention, the input signal is encoded every n bits, so that N=
Obtain 2n types of symbols. The phase of the PN sequence is this N
By changing the method according to the type, it is possible to transmit n times more information than the binary spread spectrum method described above with the same bandwidth.
【００１０】図１はこのような本発明を実施するための
通信装置全体の系統図であり、（ａ）は送信部、（ｂ）
は受信部を示す。送信部において、入力されたシリアル
信号はｎビット毎に１シンボルとしてシリアル／パラレ
ル（Ｓ／Ｐ）変換回路１１でまとめられ、多相拡散部１
２に入力され、そこで多相拡散された送信信号を得る。
同期信号の多重方法としては４相位相変調の直交軸を適
用し、ＱＰＳＫ変調器１４において、多相拡散部１２か
らの送信信号をＩ軸に、同期発生部１３からの同期信号
をＱ軸にしてＱＰＳＫ変調して伝送信号（変調出力）を
出力する。FIG. 1 is a system diagram of the entire communication device for implementing the present invention, in which (a) shows a transmitting section, and (b) shows a communication device for carrying out the present invention.
indicates the receiving section. In the transmitting section, the input serial signal is combined into one symbol for every n bits in a serial/parallel (S/P) conversion circuit 11, and then sent to a multiphase spreading section 1.
2, where a polyphase spread transmission signal is obtained. The orthogonal axes of four-phase phase modulation are applied as a multiplexing method for synchronization signals, and in the QPSK modulator 14, the transmission signal from the multiphase spreading unit 12 is used as the I axis, and the synchronization signal from the synchronization generation unit 13 is used as the Q axis. A transmission signal (modulated output) is output after QPSK modulation.
【００１１】なお、同期信号の多重方法としては、上記
方法の他に、伝送信号中に同期符号を時間軸多重する方
法があり、さらに同期信号として全く別の信号（ビーコ
ンや既存の放送波など）を用い、これを別のチャンネル
を用いて伝送する方法なども考えられる。[0011] In addition to the method described above, as a method for multiplexing a synchronization signal, there is a method of time-axis multiplexing a synchronization code in a transmission signal. ) and transmitting it using another channel.
【００１２】受信部においては、入力信号からＩ，Ｑそ
れぞれをＱＰＳＫ復調器１５で復調する。Ｑ軸信号を同
期検出用ＭＦ１７に入力してそこから拡散信号の開始点
の同期タイミングを得る。Ｉ軸からの信号は巡回型ＭＦ
１６に入力され、そこで同期検出用ＭＦ１７からの同期
信号との位相差を検出し信号が復調される。巡回型ＭＦ
１６によって得られた位相情報をパラレル／シリアル（
Ｐ／Ｓ）変換回路１８でＰ／Ｓ変換して元の信号を復元
する。In the receiving section, a QPSK demodulator 15 demodulates I and Q from the input signal. The Q-axis signal is input to the synchronization detection MF 17, and the synchronization timing of the starting point of the spread signal is obtained therefrom. The signal from the I-axis is a cyclic MF
16, where the phase difference with the synchronization signal from the synchronization detection MF 17 is detected and the signal is demodulated. Itinerant midfielder
The phase information obtained by 16 is converted into parallel/serial (
A P/S conversion circuit 18 performs P/S conversion to restore the original signal.
【００１３】図２は多相拡散部１２の詳細を示す。この
多相拡散部１２は、２ｎ 種類の位相のＰＮ信号を発生
する２ｎ 個の発生器２１と、それらの出力をＳ／Ｐ変
換回路１１からのｎビットのシンボルに基づいて切り替
えて出力するセレクタ２２から構成され、最大２ｎ 種
類の位相の異なる拡散信号からなる多相スペクトラム拡
散信号を得るものである。FIG. 2 shows details of the multiphase diffusion section 12. This multiphase spreading unit 12 includes 2n generators 21 that generate PN signals of 2n types of phases, and a selector that switches and outputs their outputs based on n-bit symbols from the S/P conversion circuit 11. 22, and obtains a multiphase spread spectrum signal consisting of a maximum of 2n types of spread signals with different phases.
【００１４】受信側においては、巡回型ＭＦ１６によっ
て相関受信による逆拡散と同時にＰＮ系列の位相を検出
する。これには二組のマッチトフィルタ（ＭＦ）を用い
る。（後述のようにしてＰＮ信号の同期はとれているも
のと仮定すると）一組のＭＦにおいては、あるフレーム
では現在伝送されている系列を１フレーム分蓄える。そ
の間他方のＭＦでは１フレーム前に蓄えた系列がどのＰ
Ｎの位相で送られてきたかを検出する。ピークを検出し
た位置とフレーム先頭との位相差から元の信号が復元で
きる。この蓄積・検出の動作を２つのＭＦで交互に繰り
返す事により小規模な受信機でも多相のＰＮ系列の検出
が可能となる。伝送されている信号は元のＰＮ系列の位
相が異なっただけであるため、その干渉除去能力は二値
伝送のものと同等と考えられる。On the receiving side, the cyclic MF 16 detects the phase of the PN sequence at the same time as despreading by correlation reception. Two sets of matched filters (MF) are used for this purpose. (Assuming that the PN signals are synchronized as described below), in a set of MFs, one frame of the currently transmitted sequence is stored in one frame. Meanwhile, in the other MF, which P is the sequence stored one frame ago?
It is detected whether the signal is sent with N phase. The original signal can be restored from the phase difference between the position where the peak was detected and the beginning of the frame. By repeating this accumulation/detection operation alternately between the two MFs, it becomes possible to detect polyphase PN sequences even with a small-scale receiver. Since the transmitted signal differs only in phase from the original PN sequence, its interference cancellation ability is considered to be equivalent to that of binary transmission.
【００１５】図３はこのような巡回型ＭＦの詳細なブロ
ック図である。すべてのスイッチ３１ａ，３１ｂ，３１
ｃは同期検出ＭＦからの同期信号によって各フレームの
開始点で切り替わる。この図の状態では一方のＭＦ３３
に現在の信号が蓄えられて行く。この間、他方のＭＦ３
２では１フレーム前に蓄えられた信号を循環させて、相
関信号をピーク位相検出回路３４に出力する。ピーク位
相検出回路３４では、巡回動作をしているＭＦ３２の出
力信号から最大のピークを得る位相を検出する。次のフ
レームではスイッチ３１ａ，３１ｂ，３１ｃが下に切り
替わり、一方のＭＦ３２に信号が入力されて行き、他方
のＭＦ３３の出力信号からピーク検出を行う。FIG. 3 is a detailed block diagram of such a cyclic MF. All switches 31a, 31b, 31
c is switched at the start point of each frame by a synchronization signal from the synchronization detection MF. In the state shown in this figure, one MF33
The current signal is stored in. During this time, the other MF3
2, the signal stored one frame before is circulated and a correlation signal is output to the peak phase detection circuit 34. The peak phase detection circuit 34 detects the phase at which the maximum peak is obtained from the output signal of the MF 32 performing a cyclic operation. In the next frame, the switches 31a, 31b, and 31c are turned down, a signal is input to one MF 32, and peak detection is performed from the output signal of the other MF 33.
【００１６】図４はＭＦの構成例を示す。ＰＮ系列を持
つｋ個の係数器４２とｋ個の遅延回路４１と加算器４３
とからなるトランスバーサル型フィルタであり、遅延回
路４１の出力を入力に戻す事で、巡回型ＭＦを構成する
ことができる。FIG. 4 shows an example of the configuration of the MF. k coefficient units 42 having a PN sequence, k delay circuits 41, and adder 43
By returning the output of the delay circuit 41 to the input, a cyclic MF can be configured.
【００１７】最後に符号の割り当ては次のように考える
。すなわち、ｍビットの帰還型シフトレジスタによるＰ
Ｎ系列（Ｍ系列）の長さはＭ＝２ｍ −１である。伝送
する符号が２のべき乗であることを考えるならば、この
Ｍ種類の位相を１つおきに割り当てれば２ｍ−１ 種類
の情報を伝送でき、２値伝送に比べて（ｍ−１）倍ビッ
トの情報を伝送できる。さらに位相情報とともに正負の
極性を考慮すればさらに１ビットの位相を伝送できるた
めにｍ倍ビットの情報を送る事が出来る。これによって
周波数利用効率はｍ倍となる。Finally, code assignment is considered as follows. In other words, P by an m-bit feedback shift register
The length of the N sequence (M sequence) is M=2m −1. Considering that the code to be transmitted is a power of 2, by assigning every other M types of phases, 2m-1 types of information can be transmitted, which is (m-1) times faster than binary transmission. Can transmit bits of information. Furthermore, if positive and negative polarities are taken into account along with phase information, one more bit of phase can be transmitted, so m times more bits of information can be transmitted. This increases the frequency utilization efficiency by m times.
【００１８】[0018]
【発明の効果】以上説明したように本発明によれば、限
られた周波数帯域で、干渉除去能力や多重能力を劣化さ
せずに伝送容量を増大することができるスペクトラム拡
散通信方式を提供することができる。[Effects of the Invention] As explained above, according to the present invention, it is possible to provide a spread spectrum communication system that can increase transmission capacity in a limited frequency band without deteriorating interference removal ability or multiplexing ability. Can be done.
【図１】本発明を実施するための通信装置全体の系統図
である。FIG. 1 is a system diagram of an entire communication device for implementing the present invention.
【図２】多相拡散部１２の詳細を示すブロック図である
。FIG. 2 is a block diagram showing details of a multiphase spreading section 12.
【図３】巡回型ＭＦの詳細なブロック図である。FIG. 3 is a detailed block diagram of a cyclic MF.
【図４】ＭＦの構成例を示す図である。FIG. 4 is a diagram showing a configuration example of an MF.
１１ Ｓ／Ｐ変換回路 １２ 多相拡散部 １３ 同期発生部 １４ ＱＰＳＫ変調器 １５ ＱＰＳＫ復調器 １６ 巡回型ＭＦ １７ 同期検出用ＭＦ １８ Ｐ／Ｓ変換回路 11 S/P conversion circuit 12 Multiphase diffusion part 13 Synchronization generation part 14 QPSK modulator 15 QPSK demodulator 16 Itinerant midfielder 17 MF for synchronization detection 18 P/S conversion circuit
Claims (1)
伝送信号における拡散符号系列の位相を入力情報に基づ
いて変化させることを特徴とするスペクトラム拡散通信
方式。[Claim 1] In a spread spectrum communication system,
A spread spectrum communication system characterized by changing the phase of a spreading code sequence in a transmission signal based on input information.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3034353A JPH04273632A (en) | 1991-02-28 | 1991-02-28 | Spread spectrum communication system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3034353A JPH04273632A (en) | 1991-02-28 | 1991-02-28 | Spread spectrum communication system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04273632A true JPH04273632A (en) | 1992-09-29 |
Family
ID=12411790
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3034353A Pending JPH04273632A (en) | 1991-02-28 | 1991-02-28 | Spread spectrum communication system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04273632A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07183829A (en) * | 1993-12-24 | 1995-07-21 | Nec Corp | Radio data communication equipment |
| JPH0951289A (en) * | 1995-08-09 | 1997-02-18 | Nec Corp | Spread spectrum communication system |
| KR970072739A (en) * | 1996-04-30 | 1997-11-07 | 스나오 다까또리 | Spectrum spread communication system for high speed communication |
| EP1046240A1 (en) * | 1998-01-05 | 2000-10-25 | Intel Corporation | A method for using circular spreading codes to achieve high bit densities in a direct-sequence spread spectrum communications system |
| JP2006339924A (en) * | 2005-06-01 | 2006-12-14 | Nec Corp | Spread spectrum communication system and demodulation circuit therefor |
| JP2007258849A (en) * | 2006-03-22 | 2007-10-04 | Nec Corp | Spread spectrum communication system and method therefor, transmitter used therefor, and receiver |
-
1991
- 1991-02-28 JP JP3034353A patent/JPH04273632A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07183829A (en) * | 1993-12-24 | 1995-07-21 | Nec Corp | Radio data communication equipment |
| US6363100B1 (en) | 1993-12-24 | 2002-03-26 | Nec Corporation | Radio data communication system using spread spectrum scheme |
| JPH0951289A (en) * | 1995-08-09 | 1997-02-18 | Nec Corp | Spread spectrum communication system |
| KR970072739A (en) * | 1996-04-30 | 1997-11-07 | 스나오 다까또리 | Spectrum spread communication system for high speed communication |
| EP1046240A1 (en) * | 1998-01-05 | 2000-10-25 | Intel Corporation | A method for using circular spreading codes to achieve high bit densities in a direct-sequence spread spectrum communications system |
| JP2006339924A (en) * | 2005-06-01 | 2006-12-14 | Nec Corp | Spread spectrum communication system and demodulation circuit therefor |
| JP4701840B2 (en) * | 2005-06-01 | 2011-06-15 | 日本電気株式会社 | Spread spectrum communication system and demodulation circuit used therefor |
| JP2007258849A (en) * | 2006-03-22 | 2007-10-04 | Nec Corp | Spread spectrum communication system and method therefor, transmitter used therefor, and receiver |
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