JPH08181680A - Code division multiple access communication method - Google Patents

Code division multiple access communication method

Info

Publication number
JPH08181680A
JPH08181680A JP6324403A JP32440394A JPH08181680A JP H08181680 A JPH08181680 A JP H08181680A JP 6324403 A JP6324403 A JP 6324403A JP 32440394 A JP32440394 A JP 32440394A JP H08181680 A JPH08181680 A JP H08181680A
Authority
JP
Japan
Prior art keywords
hopping
frequency
information
signal
multiple access
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
Application number
JP6324403A
Other languages
Japanese (ja)
Inventor
Tetsuo Mabuchi
哲男 馬渕
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Priority to JP6324403A priority Critical patent/JPH08181680A/en
Publication of JPH08181680A publication Critical patent/JPH08181680A/en
Pending legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69—Spread spectrum techniques
    • H04B1/713—Spread spectrum techniques using frequency hopping
    • H04B1/7143—Arrangements for generation of hop patterns

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

PURPOSE: To attain communication with high reliability by arranging a hopping frequency of an incoming line and a hopping frequency of an outgoing line in the same frequency band in mixture so as to enhance the frequency diversity effect. CONSTITUTION: An information signal through an outgoing line from a base station 1 to a mobile station 2. is given to an information modulation demodulation section 5 in the base station 1, in which the information is modulated based on the information signal. The signal modulated by the information is given to a spread modulation demodulation section 6, where the signal is subject to spread modulation by a hopping frequency changing in response to a hopping series generated by a hopping series section 7. The signal subject to spread modulation is sent from an antenna 11 and received by the mobile station 21 . The received signal is given in a spread modulation demodulation section 81 , where the signal is spread demodulated depending on the hopping series generated synchronously with the same hopping series as the transmission section in a hopping series section 91 and the information is demodulated by an information modulation demodulation section 101 , from which an information signal is outputted.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、基地局と複数の移動局
との間の符号分割多元接続通信方法に関し、特に、周波
数ホッピング方法によるスペクトル拡散変調により上り
回線と下り回線とを多重化する符号分割多元接続通信方
法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a code division multiple access communication method between a base station and a plurality of mobile stations, and more particularly to multiplexing uplink and downlink by spread spectrum modulation by a frequency hopping method. The present invention relates to a code division multiple access communication method.

【０００２】[0002]

【従来の技術】基地局と多数の移動局とを無線伝送路で
接続する移動通信システムに対し、周波数利用効率の向
上のために、スペクトル拡散（ＳＳ；spread spectru
m）通信方法を適用することが試みられている。スペク
トル拡散通信における拡散変調方法としては、伝送す
べき情報信号によって変調された信号に対し、疑似雑音
（ＰＮ；pseudo noise）系列を直接乗算することによっ
て広帯域にスペクトルを拡散させる直接拡散（ＤＳ；di
rect sequence）法と、ホッピング系列に対応して周
波数シンセサイザを駆動し、情報信号によって変調され
た信号の送信周波数を変化（ホップ）させることによっ
て一様にスペクトルを拡散する周波数ホッピング（Ｆ
Ｈ；frequency hopping）法とがある。そして、移動局
に応じて擬似雑音系列やホッピング系列を異ならせるこ
とにより、同一周波数帯を用いて複数の移動局と同時に
通信すること（符号分割多元接続通信）が可能になる。
特に周波数ホッピング法は、遠近問題がないため送信電
力制御をする必要がなく、また、周波数ダイバーシティ
効果があるため周波数選択性フェージングに対して強い
という利点がある。2. Description of the Related Art For a mobile communication system in which a base station and a large number of mobile stations are connected by a radio transmission path, spread spectrum (SS) is used to improve frequency utilization efficiency.
m) Attempts to apply communication methods. A spread modulation method in spread spectrum communication is direct spread (DS; di) in which a signal modulated by an information signal to be transmitted is directly multiplied by a pseudo noise (PN) sequence to spread the spectrum in a wide band.
rect sequence) method and frequency hopping (F) for uniformly spreading the spectrum by driving the frequency synthesizer corresponding to the hopping sequence and changing (hopping) the transmission frequency of the signal modulated by the information signal.
H; frequency hopping) method. Then, by making the pseudo-noise sequence and the hopping sequence different depending on the mobile station, it is possible to simultaneously communicate with a plurality of mobile stations using the same frequency band (code division multiple access communication).
In particular, the frequency hopping method has the advantages that it does not require transmission power control because it has no near-far problem, and that it is strong against frequency selective fading because it has a frequency diversity effect.

【０００３】移動通信においては、基地局と移動局とは
上り回線と下り回線とを用いて相互に通信を行う。上り
回線と下り回線は、一般に、周波数帯を分離して設定さ
れる。周波数ホッピング法による場合、例えば図４に示
すように、上り回線と下り回線とで合計８個のホッピン
グ周波数（ｆ0〜ｆ7）が割り当てられているとき、下り
回線で使用するホッピング周波数として（ｆ4〜ｆ7）、
上り回線で使用するホッピング周波数として（ｆ0〜
ｆ3）を用いることにより、上り回線と下り回線の周波
数帯を分離している。なお、図４に示した例では、各チ
ップｔ0,ｔ1,…に対してそれぞれの周波数を割り当てる
ことにより、基地局と１局の移動局との間の上り回線で
は（ｆ3,ｆ1,ｆ2,ｆ0,ｆ3）、下り回線では（ｆ5,ｆ6,
ｆ4,ｆ7,ｆ5）という時間的順序で、ホッピング周波数
を使用している。In mobile communication, a base station and a mobile station communicate with each other using an uplink and a downlink. Generally, frequency bands are set separately for the uplink and the downlink. In the case of the frequency hopping method, for example, as shown in FIG. 4, when a total of eight hopping frequencies (f 0 to f 7 ) are allocated to the uplink and the downlink, the hopping frequency used in the downlink ( f 4 to f 7 ),
As the hopping frequency used on the uplink (f 0 ~
f 3 ) is used to separate the frequency bands of the uplink and the downlink. In the example shown in FIG. 4, by assigning respective frequencies to the chips t 0 , t 1 , ..., In the uplink between the base station and one mobile station, (f 3 , f 1 , f 2 , f 0 , f 3 ) and (f 5 , f 6 ,
The hopping frequencies are used in the temporal order of f 4 , f 7 , f 5 ).

【０００４】また、特開平６−１０４８６５号公報に
は、符号分割多元接続通信方式に関し、上り回線と下り
回線とで同一搬送波周波数を用い、時分割多重化して通
信を行うことにより、フェージングに対しても高精度の
送信電力制御を実現する技術が開示されている。Further, Japanese Unexamined Patent Publication No. 6-104865 discloses a code division multiple access communication system, in which the same carrier frequency is used for the up-link and the down-link, and communication is performed by time-division multiplexing to prevent fading. However, a technique for realizing highly accurate transmission power control is disclosed.

【０００５】[0005]

【発明が解決しようとする課題】移動通信等で符号分割
多元接続通信を実現しようとする場合、周波数選択性フ
ェージングが大きな障害となる。周波数ホッピング法
は、周波数ダイバーシティ効果があるためもともと周波
数選択性フェージングに対して強いと言われているが、
上り回線と下り回線の周波数帯を分離した場合には、ど
ちらか一方の周波数帯が周波数選択性フェージング等の
影響を受けた場合に、その回線の信頼性が低くなる。ま
た、特開平６−１０４８６５号公報に開示された技術
は、高精度の送信電力制御を実現することを目的とした
ものであって、符号分割の他に時分割を行うために、装
置が複雑になるという問題点がある。When trying to realize code division multiple access communication in mobile communication or the like, frequency selective fading becomes a major obstacle. The frequency hopping method is originally said to be strong against frequency selective fading because it has a frequency diversity effect.
When the frequency bands of the uplink and the downlink are separated, the reliability of the line becomes low when either one of the frequency bands is affected by frequency selective fading or the like. Further, the technique disclosed in Japanese Patent Laid-Open No. 6-104865 is intended to realize highly accurate transmission power control, and the apparatus is complicated because time division is performed in addition to code division. There is a problem that becomes.

【０００６】本発明の目的は、周波数ホッピング法を用
いた符号分割多元接続通信方法において、広帯域の周波
数範囲で周波数選択性フェージング等の影響を受けた場
合であっても、周波数ダイバーシティ効果を高めること
により信頼性の高い通信ができるようにすることにあ
る。An object of the present invention is to improve the frequency diversity effect in a code division multiple access communication method using the frequency hopping method even when affected by frequency selective fading in a wide frequency range. To enable highly reliable communication.

【０００７】[0007]

【課題を解決するための手段】本発明の符号分割多元接
続通信方法は、基地局と複数の移動局とがスペクトル拡
散変調による通信を行う符号分割多元接続通信方法にお
いて、スペクトル拡散変調方法として周波数ホッピング
方法を用い、同一の周波数帯内に、上り回線で使用され
るホッピング周波数と下り回線で使用されるホッピング
周波数とを混在させて多重化を行う。例えば、前記周波
数帯において、上り回線で使用されるホッピング周波数
と下り回線で使用されるホッピング周波数が、交互に出
現するようにする。A code division multiple access communication method of the present invention is a code division multiple access communication method in which a base station and a plurality of mobile stations communicate by spread spectrum modulation. By using the hopping method, the hopping frequency used in the uplink and the hopping frequency used in the downlink are mixed and multiplexed in the same frequency band. For example, in the frequency band, the hopping frequency used in the uplink and the hopping frequency used in the downlink appear alternately.

【０００８】[0008]

【作用】本発明では、同一の周波数帯内で異なったホッ
ピング周波数が得られるように、この周波数帯内で上り
回線のホッピング周波数と下り回線のホッピング周波数
とを混在して配置しているので、上り回線と下り回線と
を周波数帯で分離した場合に比べ、ホッピング周波数の
分布がそれぞれの回線について広帯域となり、周波数ダ
イバーシティ効果がより顕著となって、広帯域での周波
数選択性フェージングの影響を受けにくくなる。In the present invention, the hopping frequency of the uplink and the hopping frequency of the downlink are mixedly arranged in this frequency band so that different hopping frequencies can be obtained in the same frequency band. Compared to the case where the uplink and downlink are separated by frequency band, the hopping frequency distribution becomes wide band for each line, the frequency diversity effect becomes more remarkable, and it is less susceptible to frequency selective fading in the wide band. Become.

【０００９】[0009]

【実施例】次に、本発明の実施例について、図面を参照
して説明する。図１は本発明の一実施例の符号分割多元
接続通信方法を説明する図である。Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a diagram for explaining a code division multiple access communication method according to an embodiment of the present invention.

【００１０】本実施例では、周波数ホッピング法を用い
た符号分割多元接続通信を行う基地局１と移動局２との
間において、例えば８つのホッピング周波数（ｆ0〜
ｆ7）からなる周波数帯を使用して送受信を行う場合
に、下り回線と上り回線とで周波数帯を分割することな
くこの周波数帯の全体を用い、上り回線にはｆ1,ｆ3,ｆ
5,ｆ 7の各ホッピング周波数、下り回線にはｆ0,ｆ2,
ｆ4,ｆ6の各ホッピング周波数を割り当てて送受信を行
う。図１において、上り回線及び下り回線に割り当てら
れているホッピング周波数が、それぞれ、時間・周波数
マトリクス３,４において斜線で示されている。一般に
移動局２は複数存在するが、上り回線及び下り回線のそ
れぞれについて、割り当てられたホッピング周波数を用
いて移動局ごとに異なるホッピング系列が割り当てら
れ、多元接続を実現している。In this embodiment, the frequency hopping method is used.
Between the base station 1 and the mobile station 2 which perform code division multiple access communication
In between, for example, eight hopping frequencies (f0~
f7When transmitting and receiving using the frequency band consisting of
In addition, do not divide the frequency band between the downlink and the uplink.
Uses the entire frequency band of the bear and f1, f3, f
Five, f 7Each hopping frequency, f for downlink0, f2,
fFour, f6Each hopping frequency of
U In Fig. 1, assigned to the uplink and downlink
The hopping frequencies are time and frequency
It is shown by hatching in the matrices 3 and 4. In general
Although there are multiple mobile stations 2, there are uplink and downlink links.
Use the assigned hopping frequency for each
Different hopping sequences are assigned to each mobile station.
It realizes multiple access.

【００１１】図２は、本実施例の符号分割多元接続通信
方法が適用される移動通信システムの例を示すブロック
図である。ここでは、１つの基地局１とＮ個の移動局２
1〜２Nからシステムが構成されており、基地局１と各移
動局２1〜２Nとは、無線回線１５によって多元接続され
ている。FIG. 2 is a block diagram showing an example of a mobile communication system to which the code division multiple access communication method of this embodiment is applied. Here, one base station 1 and N mobile stations 2
The system is composed of 1 to 2 N , and the base station 1 and each of the mobile stations 2 1 to 2 N are multi-connected by a wireless line 15.

【００１２】基地局１には、情報信号の変復調を行う情
報変復調部５と、ホッピング系列を発生するホッピング
系列部７と、生成したホッピング系列に基づいて変化す
るホッピング周波数によって拡散変復調を行う拡散変復
調部６と、アンテナ１１とが設けられている。同様に、
各移動局２1〜２Nには、情報信号の変復調を行う情報変
復調部１０1〜１０Nと、各移動局２1〜２Nごとにその移
動局に割り当てられたホッピング系列を生成するホッピ
ング系列部９1〜９Nと、生成したホッピング系列に基づ
いて変化するホッピング周波数によって拡散変復調を行
う拡散変復調部８1〜８Nと、アンテナ１２1〜１２Nとが
設けられている。上述したように、各移動局２1〜２Nに
割り当てられるホッピング系列は、それぞれ異なってい
る。In the base station 1, an information modulator / demodulator 5 that modulates / demodulates an information signal, a hopping sequence unit 7 that generates a hopping sequence, and a spread modulator / demodulator that performs spread modulation / demodulation with a hopping frequency that changes based on the generated hopping sequence. The section 6 and the antenna 11 are provided. Similarly,
Each of the mobile stations 2 1 to 2 N includes an information modulator / demodulator 10 1 to 10 N that modulates and demodulates an information signal, and a hopping sequence that generates a hopping sequence assigned to each mobile station 2 1 to 2 N. The sequence units 9 1 to 9 N , spread modulation / demodulation units 8 1 to 8 N that perform spread modulation / demodulation at a hopping frequency that changes based on the generated hopping sequence, and antennas 12 1 to 12 N are provided. As described above, the hopping sequences assigned to the mobile stations 2 1 to 2 N are different from each other.

【００１３】基地局１から移動局２1に向かう下り回線
では、基地局１において情報信号が情報変復調部５に入
力し、この情報信号に基づいた情報変調が行われる。情
報変調された信号は、拡散変復調部６に入力し、ホッピ
ング系列部７の生成するホッピング系列に応じて変化す
るホッピング周波数によって拡散変調を受ける。拡散変
調された信号はアンテナ１１から送出され、移動局２1
で受信される。移動局２1では、受信された信号が、ホ
ッピング系列部９1で送信側と同じホッピング系列と同
期させて発生されたホッピング系列に応じて、拡散変復
調部８1において拡散復調され、情報変復調部１０1で情
報復調され、情報信号として情報変復調部１０1から出
力される。また、移動局２1から基地局１に向かう上り
回線でも同様の過程によってデータの伝送が行われ、他
の移動局と基地局１との間でも同様に伝送が行われる。In the downlink from the base station 1 to the mobile station 2 1 , an information signal is input to the information modulator / demodulator 5 in the base station 1 and information modulation is performed based on this information signal. The information-modulated signal is input to the spread modulator / demodulator 6 and spread-modulated by the hopping frequency that changes according to the hopping sequence generated by the hopping sequence unit 7. The spread-modulated signal is transmitted from the antenna 11 and the mobile station 2 1
Will be received at. In the mobile station 2 1 , the received signal is spread and demodulated in the spreading modulator / demodulator 8 1 in accordance with the hopping sequence generated in the hopping sequence unit 9 1 in synchronization with the same hopping sequence as the transmitting side, and the information modulator / demodulator is information demodulated by 10 1, output from the information modulation and demodulation unit 10 1 as an information signal. Data is also transmitted in the same process on the uplink from the mobile station 2 1 to the base station 1, and similarly between other mobile stations and the base station 1.

【００１４】図３は、本実施例での、基地局とある１局
の移動局との間における、上り回線及び下り回線での時
間とホッピング周波数との関係を表した図である。ここ
では、上下の回線に対して全体で８ホッピング周波数か
らなる周波数帯が割り当てられており、これらのホッピ
ング周波数ｆ0〜ｆ7が縦軸に示されている。一方、横軸
は時間を示しており、ここでは、５チップｔ0〜ｔ4で１
データシンボル時間が構成されているものとする。図に
示されるように、基地局とある１局の移動局との間で
は、上り回線では（ｆ7,ｆ3,ｆ5,ｆ1,ｆ7）、下り回線
では（ｆ2,ｆ4,ｆ0,ｆ6,ｆ2）という時間的順序でホッ
ピング周波数を使用している。FIG. 3 is a diagram showing the relationship between the time on the uplink and the downlink and the hopping frequency between the base station and one mobile station in this embodiment. Here, a frequency band consisting of 8 hopping frequencies is allocated to the upper and lower lines, and these hopping frequencies f 0 to f 7 are shown on the vertical axis. On the other hand, the horizontal axis represents time, and here, 5 chips t 0 to t 4 are 1
It is assumed that the data symbol time is configured. As shown in the figure, between the base station and one mobile station, (f 7 , f 3 , f 5 , f 1 , f 7 ) is on the uplink and (f 2 , f 4 is on the downlink. , f 0 , f 6 , f 2 ) are used in the temporal order.

【００１５】このように本実施例では、上り回線と下り
回線のホッピング周波数が同一周波数帯（ｆ0〜ｆ7で構
成される周波数帯）の中で混在しているため、広帯域の
周波数範囲が周波数選択性フェージング等の影響を受け
た場合でも、周波数ダイバーシティ効果が期待できる。
例えばこの実施例で（ｆ0〜ｆ3）の周波数範囲がフェー
ジングの影響を受けた場合、従来の方法では上り回線の
全チップが影響を受けるのに対して、本発明では影響を
受けないチップもあるので、そのチップを利用して復調
することにより、高い信頼性が得られる。また、本実施
例では、上り回線と下り回線のホッピング周波数を交互
に混在しているが、任意の位置で混在させることも可能
である。As described above, in this embodiment, since the hopping frequencies of the uplink and the downlink are mixed in the same frequency band (frequency band composed of f 0 to f 7 ), the frequency range of the wide band is wide. Even when affected by frequency selective fading, the frequency diversity effect can be expected.
For example, when the frequency range of (f 0 to f 3 ) is affected by fading in this embodiment, all the chips in the uplink are affected by the conventional method, whereas the chips not affected by the present invention. Therefore, high reliability can be obtained by demodulating using the chip. Further, in the present embodiment, the uplink and downlink hopping frequencies are alternately mixed, but they can be mixed at any position.

【００１６】[0016]

【発明の効果】以上説明したように本発明は、同一周波
数帯内で上り回線のホッピング周波数と下り回線のホッ
ピング周波数とを混在して配置することにより、広帯域
に周波数ホッピングが行われることになって、広帯域の
周波数範囲に影響を与える周波数選択性フェージングに
対しても周波数ダイバーシティ効果を実現でき、信頼度
の高い通信が行えるようになるという効果がある。As described above, according to the present invention, frequency hopping is performed in a wide band by arranging the uplink hopping frequency and the downlink hopping frequency in a mixed manner in the same frequency band. As a result, the frequency diversity effect can be realized even with respect to the frequency selective fading that affects the frequency range of the wide band, and the communication with high reliability can be performed.

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

【図１】本発明の一実施例の符号分割多元接続通信方法
を説明する図である。FIG. 1 is a diagram illustrating a code division multiple access communication method according to an embodiment of the present invention.

【図２】図１に示す実施例の符号分割多元接続通信方法
が適用される移動通信システムの構成を示すブロック図
である。FIG. 2 is a block diagram showing a configuration of a mobile communication system to which the code division multiple access communication method of the embodiment shown in FIG. 1 is applied.

【図３】図１に示す実施例でのホッピング系列の時間・
周波数マトリクスである。FIG. 3 is a time chart of a hopping sequence in the embodiment shown in FIG.
It is a frequency matrix.

【図４】従来の符号分割多元接続通信方法におけるホッ
ピング系列の時間・周波数マトリクスである。FIG. 4 is a time-frequency matrix of hopping sequences in a conventional code division multiple access communication method.

【符号の説明】[Explanation of symbols]

１ 基地局 ２,２1〜２N 移動局 ３,４ 時間・周波数マトリクス ５,１０1〜１０N 情報変復調部 ６,８1〜８N 拡散変復調部 ７,９1〜９N ホッピング系列 １１,１２1〜１２N アンテナ １５ 無線回線 ｆ0〜ｆ7 ホッピング周波数 ｔ0〜ｔ4 チップ1 base station 2,2 1 to 2 N mobile station 3,4 time / frequency matrix 5,10 1 to 10 N information modulator / demodulator 6,8 1 to 8 N spreading modulator / demodulator 7,9 1 to 9 N hopping sequence 11, 12 1 to 12 N antenna 15 wireless line f 0 to f 7 hopping frequency t 0 to t 4 chip

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 基地局と複数の移動局とがスペクトル拡
散変調による通信を行う符号分割多元接続通信方法にお
いて、スペクトル拡散変調方法として周波数ホッピング
方法を用い、同一の周波数帯内に、上り回線で使用され
るホッピング周波数と下り回線で使用されるホッピング
周波数とを混在させて多重化を行うことを特徴とする符
号分割多元接続通信方法。1. A code division multiple access communication method in which a base station and a plurality of mobile stations communicate by spread spectrum modulation, wherein a frequency hopping method is used as a spread spectrum modulation method, and an uplink is used in the same frequency band. A code division multiple access communication method, wherein the hopping frequency used and the hopping frequency used in the downlink are mixed and multiplexed. 【請求項２】 上り回線で使用されるホッピング周波数
と下り回線で使用されるホッピング周波数が、前記周波
数帯において交互に出現する請求項１に記載の符号分割
多元接続通信方法。2. The code division multiple access communication method according to claim 1, wherein the hopping frequency used in the uplink and the hopping frequency used in the downlink alternately appear in the frequency band.
JP6324403A 1994-12-27 1994-12-27 Code division multiple access communication method Pending JPH08181680A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6324403A JPH08181680A (en) 1994-12-27 1994-12-27 Code division multiple access communication method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6324403A JPH08181680A (en) 1994-12-27 1994-12-27 Code division multiple access communication method

Publications (1)

Publication Number Publication Date
JPH08181680A true JPH08181680A (en) 1996-07-12

Family

ID=18165414

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6324403A Pending JPH08181680A (en) 1994-12-27 1994-12-27 Code division multiple access communication method

Country Status (1)

Country Link
JP (1) JPH08181680A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09214404A (en) * 1995-11-29 1997-08-15 Nec Corp Spread spectrum communication method and device
US5887023A (en) * 1995-11-29 1999-03-23 Nec Corporation Method and apparatus for a frequency hopping-spread spectrum communication system

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6486638A (en) * 1987-09-29 1989-03-31 Hitachi Ltd Frequency hopping radio communication system
JPH04334222A (en) * 1991-05-10 1992-11-20 Japan Radio Co Ltd Spread spectrum communication system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6486638A (en) * 1987-09-29 1989-03-31 Hitachi Ltd Frequency hopping radio communication system
JPH04334222A (en) * 1991-05-10 1992-11-20 Japan Radio Co Ltd Spread spectrum communication system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09214404A (en) * 1995-11-29 1997-08-15 Nec Corp Spread spectrum communication method and device
US5887023A (en) * 1995-11-29 1999-03-23 Nec Corporation Method and apparatus for a frequency hopping-spread spectrum communication system

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