JPS6266729A - Same frequency repeating system - Google Patents

Same frequency repeating system

Info

Publication number
JPS6266729A
JPS6266729A JP20706785A JP20706785A JPS6266729A JP S6266729 A JPS6266729 A JP S6266729A JP 20706785 A JP20706785 A JP 20706785A JP 20706785 A JP20706785 A JP 20706785A JP S6266729 A JPS6266729 A JP S6266729A
Authority
JP
Japan
Prior art keywords
signal
frequency
transmission
route
interference
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.)
Granted
Application number
JP20706785A
Other languages
Japanese (ja)
Other versions
JPH0611125B2 (en
Inventor
Toshihiko Ryu
龍 敏彦
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 JP20706785A priority Critical patent/JPH0611125B2/en
Priority to AU62767/86A priority patent/AU588176B2/en
Priority to EP86112842A priority patent/EP0215479B1/en
Priority to CA000518349A priority patent/CA1250022A/en
Priority to DE8686112842T priority patent/DE3681388D1/en
Priority to US06/908,847 priority patent/US4789993A/en
Publication of JPS6266729A publication Critical patent/JPS6266729A/en
Publication of JPH0611125B2 publication Critical patent/JPH0611125B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B7/00Radio transmission systems, i.e. using radiation field
    • H04B7/14Relay systems
    • H04B7/15Active relay systems
    • H04B7/155Ground-based stations
    • H04B7/15564Relay station antennae loop interference reduction

Landscapes

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

Abstract

PURPOSE:To eliminate an interference between transmission and reception signals by interchanging mutually frequencies used in individual routes at every repeating station when a common-frequency radio communication line of plural routes is repeated. CONSTITUTION:A reception signal 101 corresponding to a route having a carrier frequency f1 passes a reception antenna 1, a receiver 2, an adding circuit 4, and a demodulator 5 and is demodulated and is modulated to a transmission signal 103 having a carrier frequency f2 by a modulator 6 and a transmitter 8 and is transmitted from a transmission antenna 9. Similarly, a reception signal 102 corresponding to a route having the carrier frequency f2 becomes a transmission signal 104 having the carrier frequency f1 by repeating and is transmitted. Then, the interference between transmission and reception is not caused because transmission and reception frequencies are different from each other on the same route, and variable frequency characteristic filters including correlation detectors 19 and 22 are used to eliminate the interference between routes. Thus, the interference between transmission and reception signals is eliminated to hold the line quality well.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は同一周波数中継方式に関し、特に送受同一の搬
送波周波数を用いる無線通信回線において、中継局にお
ける送信信号の受信信号に対する干渉による回線品質の
劣化を改善する同一周波数中継方式に関する。
Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a same frequency relay system, and in particular, in a wireless communication line that uses the same carrier frequency for transmission and reception, it is possible to reduce line quality due to interference of a transmitted signal with a received signal at a relay station. This invention relates to a same frequency repeating system that improves deterioration.

〔従来例〕[Conventional example]

従来、中継局を介して形成されるマイクロ波帯の無線通
信回線においては、いわゆる2周波方式が用いられてお
シ、同一局における送信と受信の周波数は、送受間にお
いて生起する干渉を防止するために相互に異なる周波数
が使用されている。
Conventionally, a so-called two-frequency system has been used in microwave band wireless communication lines formed via relay stations, and the frequencies of transmission and reception at the same station are set to prevent interference between transmission and reception. Different frequencies are used for this purpose.

従って、無線通信回線における各中継局においては、各
中継区間ごとに゛送受信周波数が交互に入れ代わる形で
周波数の割振シが行われている。しかしながら、最近、
マイクロ波帯の無線通信回縁に割当てられる使用周波数
の有効利用という観点が回線の適用が提案されている。
Therefore, at each relay station in a wireless communication line, frequency allocation is performed in such a way that the transmission and reception frequencies are alternated for each relay section. However, recently,
The application of lines has been proposed from the viewpoint of effective use of the frequencies allocated to wireless communication lines in the microwave band.

第2図に示されるのは、上記同一周波数無線通信回線に
おける、中継局の1ルートの一方向に対応する中継シス
テムの主要部を示すブロック図で、受信アンテナ25と
、受信器26と、受信信号の搬送波周波数を所定の中間
周波数に変換するための局部発振信号を発生する局部発
振器27と、復調器28と、変調器29と、搬送波発生
回路30と、送信器31と、送信信号の搬送波周波数を
生成するための周波数変換用の局部発振信号を発生する
局部発振器32と、送信アンテナ32とを備えている。
What is shown in FIG. 2 is a block diagram showing the main parts of a relay system corresponding to one direction of one route of a relay station in the same frequency wireless communication line, including a receiving antenna 25, a receiver 26, and a receiving antenna 25, a receiver 26, A local oscillator 27 that generates a local oscillation signal for converting the carrier frequency of a signal to a predetermined intermediate frequency, a demodulator 28, a modulator 29, a carrier generation circuit 30, a transmitter 31, and a carrier wave for a transmission signal. It includes a local oscillator 32 that generates a local oscillation signal for frequency conversion to generate a frequency, and a transmitting antenna 32.

第2図において、搬送波周波数がflの受信信号105
は、受信アンテナ25を介して受信器26に入力される
。受信器26には周波数変換器および中間周波増幅器等
が備えられておシ、局部発振器27から送られてくる局
部発振信号によシ、受信信号105は所定の中間周波信
号に変換され、前記中間周波増幅器によシ増幅されて復
調器28に入力される。復調器28は、例えばディジタ
ル多相位相変調波またはティジタル多値直交振幅変調波
等の入力に対応して、復満方式としては直交位相周期検
波方式を用いて構成されておυ、また、受信信号に含ま
れている振幅歪ならびに位相歪を除去するための等化回
路等が備えられている。
In FIG. 2, a received signal 105 with a carrier frequency fl
is input to the receiver 26 via the receiving antenna 25. The receiver 26 is equipped with a frequency converter, an intermediate frequency amplifier, etc., and according to the local oscillation signal sent from the local oscillator 27, the received signal 105 is converted into a predetermined intermediate frequency signal, and the received signal 105 is converted into a predetermined intermediate frequency signal. The signal is amplified by a frequency amplifier and input to the demodulator 28. The demodulator 28 is configured to use a quadrature phase periodic detection method as a demodulation method in response to the input of, for example, a digital multiphase phase modulated wave or a digital multilevel quadrature amplitude modulated wave. It is equipped with an equalization circuit and the like for removing amplitude distortion and phase distortion contained in the signal.

復調器28において復調されて出力される復調信号は変
調器29に入力され、搬送波発生回路30から送られて
くる搬送波信号に対する前記復調信号による変調作用が
行われる。変調器29から出力される被変調波信号は送
信器31に入力され、局部発振器32から送られてくる
局部発振信号によシ、受信信号105の搬送波周波数f
1に等しい搬送波周波数の送信信号に変換され、電力増
幅されて送信信号106として送信アンテナ33より対
向局に送出される。この同一周波数中継方式においては
、送信および受信の周波数が同一であるために、中継局
自体において送信信号の受信信号に対する漏れ込みによ
る干渉信号が発生するが、この干渉信号に対する対策と
しては、復調器28に備えられている前記等化回路によ
シ干渉信号を除去することが考慮されている。
The demodulated signal demodulated and output by the demodulator 28 is input to the modulator 29, where the demodulated signal modulates the carrier signal sent from the carrier wave generation circuit 30. The modulated wave signal output from the modulator 29 is input to the transmitter 31, and depending on the local oscillation signal sent from the local oscillator 32, the carrier wave frequency f of the received signal 105 is
The signal is converted into a transmission signal with a carrier frequency equal to 1, power amplified, and transmitted as a transmission signal 106 from the transmission antenna 33 to the opposite station. In this same frequency relay method, since the transmitting and receiving frequencies are the same, interference signals are generated at the relay station itself due to leakage of the transmitted signal to the received signal.As a countermeasure against this interference signal, the demodulator It is considered that the equalization circuit provided in 28 removes the interference signal.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

上述の同一周波数中継方式においては、受信信号ならび
に送信信号に対するベースバンド信号が同一であるため
に、本来の受信信号のベースバンド信号と送信信号の漏
れ込みによる干渉信号のベースバンド信号との間の相互
相関が大となシ、従って、前記本来の受信信号と前記干
渉信号との識別が極めて困難となるため、送信信号の受
信信号に対する漏れ込みによる干渉信号を十分に除去し
得ないという欠点がある。
In the above-mentioned same frequency relay method, since the baseband signals for the received signal and the transmitted signal are the same, there is a difference between the baseband signal of the original received signal and the baseband signal of the interference signal due to leakage of the transmitted signal. Since the cross-correlation is large, and therefore it is extremely difficult to distinguish between the original received signal and the interference signal, there is a drawback that the interference signal caused by the leakage of the transmitted signal to the received signal cannot be sufficiently removed. be.

〔問題点を解決するための手段〕[Means for solving problems]

上述の問題点を解決するために、本発明の同一周波数中
継方式は、複数ルートの同一周波数無線通信回線の中継
局において、前記複数ルートにおける各ルートに対応す
る中継システムごとに、受信周波数と送信周波数とを異
なる周波数に設定する手段を備えている。
In order to solve the above-mentioned problems, the same frequency relaying method of the present invention has a relay station of the same frequency wireless communication line of multiple routes, and the receiving frequency and the transmitting frequency are adjusted for each relay system corresponding to each route in the multiple routes. A means for setting the frequency to a different frequency is provided.

〔実施例〕〔Example〕

以下、本発明について図面を参照して説明する。 Hereinafter, the present invention will be explained with reference to the drawings.

第1図は、本発明の一実施例における一対の中継システ
ムの主要部を示すブロック図である。第1図に示される
ように、本中継システムは、受信アンテナ1および10
と、受信器2および11と、局部発振器3および12と
、加算回路4および14と、復調器5および15と、変
調器6および13と、搬送波発生回路7および16と、
送信器8および17と、送信アンテナ9および18と、
相関検出器19およびトランスバーサル・フィルタ20
を含む可変周波数特性フィルタ21と、相関検出器22
およびトランスパーサル−フィルタ23を含む可変周波
数特性フィルタ24とを備えている。
FIG. 1 is a block diagram showing the main parts of a pair of relay systems in one embodiment of the present invention. As shown in FIG. 1, this relay system includes receiving antennas 1 and 10.
, receivers 2 and 11, local oscillators 3 and 12, adder circuits 4 and 14, demodulators 5 and 15, modulators 6 and 13, carrier wave generation circuits 7 and 16,
transmitters 8 and 17; transmitting antennas 9 and 18;
Correlation detector 19 and transversal filter 20
a variable frequency characteristic filter 21 including a correlation detector 22
and a variable frequency characteristic filter 24 including a transversal filter 23.

第1図において、搬送波周波数がflおよびflの2ル
ートに対応する受信信号101および102は、それぞ
れ受信アンテナ1および10を介して受信器2および1
1に入力される。受信器2および11には、それぞれ周
波数変換器および中間周波増幅器等が備えられておシ、
それぞれ局部発振器3および12から送られてくる局部
発振信号により、受信信号101および102は所定の
中間周波信号に変換され、前記中間周波増幅器により増
幅されて、それぞれ対応する加算回路4および13に入
力される。加算回路4および13においては、それぞれ
可変周波数特性フィルタ21および24に含まれるトラ
ンスバーサル・フィルタ20および23から送られてく
る干渉消去信号111および112と加算され、受信信
号に漏れ込んでいる送信信号による干渉信号が削減され
て、それぞれ復調器5および14に入力される。復調器
5および14は、例えばディジタル多相位相変調波また
はディジタル多値直交振幅変調波等の入力に対応して、
復調方式としては直交位相同期検波方式によシ構成され
ておシ、それぞれの復調器5および14から出力される
復調信号105および106は、それぞれ変調器6およ
び相関検出器22と、変調器15および相関検出器19
とに送られる。変調器6および15においては、それぞ
れ対応する前記復調信号をベースバンド信号として、そ
れぞれ搬送波発生回路7および16から入力される所定
の搬送波信号が変調され、それぞれの被変調波信号11
3および114は、対応する送信器8および17に送ら
れるとともに、それぞれトランスバーサル・フィルタ2
3および2oにモ送られる。送信器8および17には、
それぞれ周波数変換器および電力増幅器等が備えられて
おシ、それぞれ局部発振器3および12よ少入力される
局部発振周波数を介して、前記被変調波信号の搬送波周
波数は、それぞれ前記搬送波周波数らおよびflK変換
され、所定の電力レベルに増幅されて、送信アンテナ9
および18より、それぞれ送信信号103および104
として対向局に送出される。
In FIG. 1, received signals 101 and 102 corresponding to two routes with carrier frequencies fl and fl are transmitted to receivers 2 and 1 via receiving antennas 1 and 10, respectively.
1 is input. The receivers 2 and 11 are each equipped with a frequency converter, an intermediate frequency amplifier, etc.
Received signals 101 and 102 are converted into predetermined intermediate frequency signals by local oscillation signals sent from local oscillators 3 and 12, respectively, amplified by the intermediate frequency amplifier, and input to corresponding adder circuits 4 and 13, respectively. be done. In adder circuits 4 and 13, interference cancellation signals 111 and 112 sent from transversal filters 20 and 23 included in variable frequency characteristic filters 21 and 24, respectively, are added, and the transmitted signal leaking into the received signal is added. The interference signals caused by the interference signals are reduced and input to demodulators 5 and 14, respectively. The demodulators 5 and 14 respond to an input of, for example, a digital multiphase phase modulated wave or a digital multilevel quadrature amplitude modulated wave, and
The demodulation method is a quadrature phase coherent detection method, and the demodulated signals 105 and 106 output from the respective demodulators 5 and 14 are sent to the modulator 6, the correlation detector 22, and the modulator 15, respectively. and correlation detector 19
sent to. In modulators 6 and 15, predetermined carrier signals inputted from carrier wave generation circuits 7 and 16, respectively, are modulated using the corresponding demodulated signals as baseband signals, and respective modulated wave signals 11 are modulated.
3 and 114 are sent to corresponding transmitters 8 and 17, and transversal filter 2, respectively.
3 and 2o. Transmitters 8 and 17 include
Each of them is equipped with a frequency converter, a power amplifier, etc., and the carrier frequency of the modulated wave signal is changed to the carrier frequency of the modulated wave signal through the local oscillation frequency inputted to the local oscillators 3 and 12, respectively. converted, amplified to a predetermined power level, and transmitted to the transmitting antenna 9.
and 18, the transmitted signals 103 and 104, respectively.
The signal is sent to the opposite station as a signal.

従って、搬送波周波数がflの受信信号に対応するルー
トにおいては、搬送波周波数がf:の送信信号103が
対応し、また、搬送波周波数がf、の受信信号102に
対応するルートにおいては、搬送波周波数がflの送信
信号104が対応しておシ、第1図に示される一対の中
継システムにおいては、それぞれ受信周波数と送信周波
数とが異なる周波数に設定される。
Therefore, in the route corresponding to the received signal with carrier frequency fl, the transmitted signal 103 with carrier frequency f: corresponds, and in the route corresponding to the received signal 102 with carrier frequency f, the carrier frequency is In the pair of relay systems shown in FIG. 1, the receiving frequency and the transmitting frequency are respectively set to different frequencies.

上述の本実施例における一対の中継システムにおいては
、受信信号101に対応するルート(以下、Aルートと
いう)における変調器6から出力きれる中間周波数帯の
被変調波信号113は、可変周波数特性フィルタ24に
含まれるトランスパープル・フィルタ23に送られる。
In the pair of relay systems in this embodiment described above, the modulated wave signal 113 in the intermediate frequency band that can be output from the modulator 6 on the route corresponding to the received signal 101 (hereinafter referred to as route A) is passed through the variable frequency characteristic filter 24. The signal is sent to a transpurple filter 23 included in the filter.

また、受信ルート102に対応するルート(以下、Bル
ートという)における変調器15から出力される中間周
波数帯の被変調波信号114は、可変周波数特性フィル
タ21に含まれるトランスバーサル・フィルタ20に送
られる。一方、Aルートにおける復調器5から出力され
る誤差信号107およびBルートにおける復調器14か
ら出力される誤差信号108は、それぞれ相関検出器1
9および22に入力される。上記のAルートの復調信号
105には、Aルートにおけるベースバンド信号とBル
ートの送信信号の漏れ込みによる干渉信号とが重畳され
ておバBルートの復調信号106には、Bルートにおけ
るベースバンド信号とAルートの送信信号の漏れ込みに
よる干渉信号とが重畳されている。また、復調器5およ
び14から出力される誤差信号107および108には
、それぞれBルートの送信信号の漏れ込みによる干渉信
号とAルートの送信信号の漏れ込みKよる干渉信号とが
介在している。従って、相関検出器19においては復調
信号106と誤差信号107との間の相互相関がとられ
、復調信号106を基準としてAルートめ受信信号に漏
れ込んでいるBルートからの干渉信号が検出され、この
干渉信号を最小とするように使用する複数の制@信号1
09が出力されで、トランスバーサル・フィルタ2oの
対応する各タップの重み付は回路に入力される。トラン
スバーサル・フィルタ20には、変調器15から出力さ
れるBルートの中間周波数帯の被変調波信号114が入
力されておシ、上記複数の制御信号109による各タッ
プの重み付は回路に対する制御作用を介して、中間周波
数帯の干渉消去信号111が出力される。この干渉消去
信号111は加算回路4に入力され、受信器2から送ら
れてくるkA−−)の中間周波数帯の受信信号に加算さ
れて、重畳されている干渉信号が豚去される。同様にし
て、相関検出器22およびトランスバーサル・フィルタ
23を含む可変周波数特性フィルタ24の作用を介して
、加算回路13に入力される干渉消去信号112によシ
、Bルートの中間周波数帯の受信信号に重畳されている
干渉信号が除去される。なお、この場合において、周波
数flおよびf2は一対の中継システム間における相互
干渉が生起しない程度に分離されておシ、同一ルートに
おける送受信信号間の干渉は存在せず問題とはならない
Further, the intermediate frequency band modulated wave signal 114 output from the modulator 15 on a route corresponding to the reception route 102 (hereinafter referred to as route B) is sent to the transversal filter 20 included in the variable frequency characteristic filter 21. It will be done. On the other hand, the error signal 107 output from the demodulator 5 on the A route and the error signal 108 output from the demodulator 14 on the B route are transmitted to the correlation detector 1, respectively.
9 and 22. The demodulated signal 105 of the A route is superimposed with the interference signal caused by the leakage of the baseband signal of the A route and the transmission signal of the B route, and the demodulated signal 106 of the B route is superimposed with the baseband signal of the A route and the interference signal caused by the leakage of the transmitted signal of the B route. The signal and the interference signal caused by the leakage of the transmission signal of route A are superimposed. Furthermore, the error signals 107 and 108 output from the demodulators 5 and 14 include an interference signal due to the leakage of the transmission signal of the B route and an interference signal due to the leakage of the transmission signal K of the A route, respectively. . Therefore, the correlation detector 19 takes the cross-correlation between the demodulated signal 106 and the error signal 107, and detects the interference signal from the B route leaking into the received signal from the A route using the demodulated signal 106 as a reference. , a plurality of control @signals 1 are used to minimize this interference signal.
09 is output, and the weighting of each corresponding tap of the transversal filter 2o is input to the circuit. The modulated wave signal 114 in the intermediate frequency band of the B route output from the modulator 15 is input to the transversal filter 20, and the weighting of each tap by the plurality of control signals 109 is controlled by the circuit. Through this action, an intermediate frequency band interference cancellation signal 111 is output. This interference canceling signal 111 is input to the adding circuit 4, where it is added to the intermediate frequency band reception signal of kA--) sent from the receiver 2, and the superimposed interference signal is eliminated. Similarly, through the action of the variable frequency characteristic filter 24 including the correlation detector 22 and the transversal filter 23, the intermediate frequency band of the B route is received by the interference cancellation signal 112 input to the adder circuit 13. Interfering signals superimposed on the signal are removed. In this case, the frequencies fl and f2 are separated to such an extent that mutual interference between the pair of relay systems does not occur, and there is no interference between transmitted and received signals on the same route, which poses no problem.

〔発明の効果〕〔Effect of the invention〕

以上説明したように、本発明は、複数ルートの同一周波
数無線通信回線に適用されて、中継局における送信信号
の受信信号に対する漏れ込みによる干渉を排除し、前記
同一周波数無線通信回線の回線品質を正常に維持するこ
とができるという効果がある。
As described above, the present invention is applied to multiple routes of the same frequency wireless communication line, eliminates interference caused by leakage of transmitted signals to received signals at relay stations, and improves line quality of the same frequency wireless communication line. It has the effect of being able to maintain normal conditions.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は、本発明の一実施例における中継局の主要部を
示すブロック図、第2図は従来例における同一周波数中
継方式における中継局の主要部を示すブロック図である
。 図において、1,10.25・・・・・・受信アンテナ
、2.22.26・・・・・・受信器、3,12,27
.32・・川・局部発振器、4.13・・・・・・加算
回路、5,14.28・・・・・・復調器、6,15.
29・・・・・・変調器、7,16゜30・・・・・・
搬送波発生回路、8,17.31・・・・・送信器、9
,18.33・・・・・・送信アンテナ、19,17゜
31・・・・・・送信器、9,18,33・・・・・・
送信アンテナ、19 、22・・・・・・相関検出器、
20.23・・・・・・トランスパーサル・フィルタ、
21.24・・・・・・可変周波数特性フィルタ。 代理人 弁理士  内 原   晋 \、。
FIG. 1 is a block diagram showing the main parts of a relay station in an embodiment of the present invention, and FIG. 2 is a block diagram showing the main parts of a relay station in a conventional same frequency relay system. In the figure, 1, 10.25...Receiving antenna, 2.22.26...Receiver, 3, 12, 27
.. 32...Local oscillator, 4.13...Addition circuit, 5,14.28...Demodulator, 6,15.
29...Modulator, 7,16°30...
Carrier wave generation circuit, 8, 17.31...Transmitter, 9
, 18.33...Transmission antenna, 19,17°31...Transmitter, 9,18,33...
Transmission antenna, 19, 22...correlation detector,
20.23...Transpersal filter,
21.24...Variable frequency characteristic filter. Agent: Susumu Uchihara, patent attorney.

Claims (2)

【特許請求の範囲】[Claims] (1)複数ルートの同一周波数無線通信回線の中継局に
おいて、前記複数ルートにおける各ルートに対応する中
継システムごとに、受信周波数と送信周波数とを異なる
周波数に設定する手段を備えることを特徴とする同一周
波数中継方式。
(1) In a relay station of the same frequency wireless communication line for multiple routes, the relay station is characterized by comprising means for setting the receiving frequency and the transmitting frequency to different frequencies for each relay system corresponding to each route in the multiple routes. Same frequency relay method.
(2)前記中継局において、各ルートごとに受信周波数
と送信周波数とを異なる周波数に設定する手段の一部と
して、受信周波数と送信周波数とが同一周波数に設定さ
れる一対の中継システム間において、各中継システムの
変調器出力側における被変調波信号を、相対応する中継
システムの復調器入力側に導入するための可変周波数特
性を有する信号波形修正手段を備えることを特徴とする
特許請求の範囲第(1)項記載の同一周波数中継方式。
(2) In the relay station, as part of the means for setting the receiving frequency and the transmitting frequency to different frequencies for each route, between a pair of relay systems in which the receiving frequency and the transmitting frequency are set to the same frequency, Claims characterized by comprising signal waveform modification means having variable frequency characteristics for introducing the modulated wave signal on the modulator output side of each relay system into the demodulator input side of the corresponding relay system. Same frequency repeating method described in paragraph (1).
JP20706785A 1985-09-18 1985-09-18 Same frequency relay system Expired - Lifetime JPH0611125B2 (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
JP20706785A JPH0611125B2 (en) 1985-09-18 1985-09-18 Same frequency relay system
AU62767/86A AU588176B2 (en) 1985-09-18 1986-09-17 One frequency repeater for a digital radio system
EP86112842A EP0215479B1 (en) 1985-09-18 1986-09-17 One frequency repeater for a digital radio system
CA000518349A CA1250022A (en) 1985-09-18 1986-09-17 One frequency repeater having interference cancellation capability in a digital radio system
DE8686112842T DE3681388D1 (en) 1985-09-18 1986-09-17 RADIO RELAY WITH ONLY ONE FREQUENCY FOR A DIGITAL RADIO SYSTEM.
US06/908,847 US4789993A (en) 1985-09-18 1986-09-18 One frequency repeater for a digital radio system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP20706785A JPH0611125B2 (en) 1985-09-18 1985-09-18 Same frequency relay system

Publications (2)

Publication Number Publication Date
JPS6266729A true JPS6266729A (en) 1987-03-26
JPH0611125B2 JPH0611125B2 (en) 1994-02-09

Family

ID=16533651

Family Applications (1)

Application Number Title Priority Date Filing Date
JP20706785A Expired - Lifetime JPH0611125B2 (en) 1985-09-18 1985-09-18 Same frequency relay system

Country Status (1)

Country Link
JP (1) JPH0611125B2 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01115228A (en) * 1987-10-29 1989-05-08 Fuji Tec Kk Radio repeater
JP2005192185A (en) * 2003-12-05 2005-07-14 Ntt Docomo Inc Radio repeater and radio relay transmission method
JP2008253865A (en) * 2007-03-30 2008-10-23 Fujifilm Corp Manufacturing method of oil-in-water type emulsion, and oil-in-water type emulsion
JP4659144B2 (en) * 2009-03-31 2011-03-30 新日本製鐵株式会社 Binder addition method, binder addition apparatus, kneader and kneading method

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01115228A (en) * 1987-10-29 1989-05-08 Fuji Tec Kk Radio repeater
JP2005192185A (en) * 2003-12-05 2005-07-14 Ntt Docomo Inc Radio repeater and radio relay transmission method
JP4523817B2 (en) * 2003-12-05 2010-08-11 株式会社エヌ・ティ・ティ・ドコモ Wireless relay device
JP2008253865A (en) * 2007-03-30 2008-10-23 Fujifilm Corp Manufacturing method of oil-in-water type emulsion, and oil-in-water type emulsion
JP4659144B2 (en) * 2009-03-31 2011-03-30 新日本製鐵株式会社 Binder addition method, binder addition apparatus, kneader and kneading method

Also Published As

Publication number Publication date
JPH0611125B2 (en) 1994-02-09

Similar Documents

Publication Publication Date Title
US4789993A (en) One frequency repeater for a digital radio system
AU564540B2 (en) Improved isolation method and apparatus for a same frequency repeater
JPS6266729A (en) Same frequency repeating system
JPH05291995A (en) Method for compensating interference for radio repeater station
WO1983001878A1 (en) Random frequency offsetting apparatus for multi-transmitter simulcast radio communications systems
EP0552692B1 (en) System for synchronizing mutually interfering signals in digital radio transmissions with frequency re-use
JPS62118645A (en) Same frequency relay system
JPH0523652B2 (en)
US3383597A (en) Multiple access satellite communication system
JP2873996B2 (en) Wireless communication device
JP2674726B2 (en) Spread spectrum communication equipment
JPH0746783B2 (en) Interference signal elimination method
JPS6313430A (en) Repeating installation for digital radiocommunication
FI112416B (en) Method and apparatus for transmitting information by radio
JP2513311B2 (en) Cross polarization communication system
JP2504184B2 (en) Cross polarization communication system
JP3208611B2 (en) Same frequency wireless communication system
JPS61161057A (en) One frequency repeater
JP2595751B2 (en) Wireless transceiver
JPH05260014A (en) System for compensating cross polarized wave interference
JPS62176232A (en) Multiplex transmission system
JP2513324B2 (en) Dual polarization transmission device
JPS61161056A (en) One frequency repeater
JPS61269430A (en) Ssb communication system
JPS61131636A (en) Polarized wave multiplex radio communication system