JPS6412136B2 - - Google Patents
Info
- Publication number
- JPS6412136B2 JPS6412136B2 JP57187713A JP18771382A JPS6412136B2 JP S6412136 B2 JPS6412136 B2 JP S6412136B2 JP 57187713 A JP57187713 A JP 57187713A JP 18771382 A JP18771382 A JP 18771382A JP S6412136 B2 JPS6412136 B2 JP S6412136B2
- Authority
- JP
- Japan
- Prior art keywords
- polarization
- signal
- circuit
- output
- control signal
- 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.)
- Expired
Links
- 230000010287 polarization Effects 0.000 claims description 39
- 230000005856 abnormality Effects 0.000 claims description 16
- 238000005388 cross polarization Methods 0.000 claims description 15
- 238000004891 communication Methods 0.000 claims description 11
- 238000001514 detection method Methods 0.000 claims description 7
- 230000008878 coupling Effects 0.000 claims description 5
- 238000010168 coupling process Methods 0.000 claims description 5
- 238000005859 coupling reaction Methods 0.000 claims description 5
- 238000000034 method Methods 0.000 description 14
- 238000010586 diagram Methods 0.000 description 10
- 230000002159 abnormal effect Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 6
- 230000003044 adaptive effect Effects 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 2
- 238000005562 fading Methods 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 230000000875 corresponding effect Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 230000003631 expected effect Effects 0.000 description 1
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J99/00—Subject matter not provided for in other groups of this subclass
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
Description
【発明の詳細な説明】
本発明は交差偏波干渉除去回路、特にデイジタ
ル無線通信に適用され、一方の偏波に異常が発生
したとき他方の偏波への波及を防止し、異常が回
復したとき復旧を促進させる手段を備えた交差偏
波干渉除去回路に関する。[Detailed Description of the Invention] The present invention is applied to a cross-polarization interference cancellation circuit, especially to digital wireless communication, and when an abnormality occurs in one polarization, it prevents the spread to the other polarization, and the abnormality is recovered. The present invention relates to a cross-polarization interference cancellation circuit having means for promoting recovery.
近年、マイクロ波無線通信では、同じ周波数の
直交した２偏波（垂直と水平または左旋円偏波と
右旋円偏波）を用いて周波数を有効に利用する直
交偏波通信方式が注目されている。このような直
交する２偏波は降雨などによる媒質の異方性のた
め交差偏波を発生し、両偏波間に交差偏波干渉が
生ずる。従来、デイジタル無線通信に適した交差
偏波干渉除去回路として、例えば特開昭55−
133156号公報に、復調されたベースバンド信号情
報に基づきトランスバーサルフイルタを制御して
交差偏波干渉を除去する回路が提案されている。
しかしながら、このような従来の回路は、受信入
力がある値以上で復調器が正常に動作している場
合には期待する効果が得られるが、後述するよう
に、一方の偏差例えば垂直Ｖ偏波がフエージング
などによる極端なレベル低下や雑音増などによつ
て、復調器の搬送波同期外れを起こし復調出力に
異常が発生すると、干渉波除去回路は正常に動作
しなくなり、逆に水平Ｈ偏波に干渉を注入してＨ
偏波の符号誤りを増大させたり、又はＨ偏波から
Ｖ偏波への干渉の流入によりＶ偏波の異常が回復
したときの制御動作の収れんを遅らせるなどの欠
点がある。 In recent years, orthogonal polarization communication methods, which utilize frequencies effectively by using two orthogonal polarized waves of the same frequency (vertical and horizontal or left-handed circularly polarized waves and right-handed circularly polarized waves), have attracted attention in microwave wireless communications. There is. Such two orthogonal polarized waves generate cross-polarized waves due to the anisotropy of the medium due to rainfall, etc., and cross-polarized waves interference occurs between the two polarized waves. Conventionally, as a cross-polarization interference removal circuit suitable for digital wireless communication, for example,
No. 133156 proposes a circuit that controls a transversal filter based on demodulated baseband signal information to eliminate cross-polarization interference.
However, such conventional circuits can achieve the expected effect when the received input exceeds a certain value and the demodulator is operating normally; If the demodulator loses carrier synchronization and an abnormality occurs in the demodulated output due to an extreme drop in level due to fading or an increase in noise, the interference wave removal circuit will not operate normally, and conversely, the horizontal H polarization Inject interference into H
There are disadvantages such as increasing polarization code errors or delaying convergence of control operations when the abnormality of V polarization is recovered due to interference flowing from H polarization to V polarization.
本発明の目的は、上述の欠点を除去し、少なく
とも一方の偏波の異常により他方の偏波を逆に劣
化させることがなく、更に異常が回復したときに
速やかに正常動作に復帰する交差偏波干渉除去回
路を提供することである。 The object of the present invention is to provide a cross polarization system which eliminates the above-mentioned drawbacks, prevents at least one polarized wave from deteriorating due to an abnormality of the other polarized wave, and which quickly returns to normal operation when the abnormality is recovered. An object of the present invention is to provide a wave interference cancellation circuit.
本発明の交差偏波干渉除去回路は、同一周波数
で互いに直交した２つの偏波を使用する直交偏波
通信方式のデイジタル変調された受信信号を復調
する少なくとも１つのデイジタル復調器と、この
デイジタル復調器の前または後に設けられ一方の
偏波の信号を他方の偏波に結合しその結合量を制
御信号によつて制御できる少なくとも１つの可変
結合器と、前記デイジタル復調器および前記可変
結合器の後に設けられ復調されたベースバンド信
号を基にして前記可変結合器の前記制御信号を発
生する制御信号発生器とを備えた交差偏波干渉除
去回路において、前記デイジタル復調器の復調出
力の異常を検出する少なくとも１つの異異常検出
手段と、この異常検出手段の出力により前記可変
結合器の少なくとも１つの出力をあらかじめ定め
た値に設定するリセツト手段を備えて構成され
る。 The cross-polarization interference cancellation circuit of the present invention includes at least one digital demodulator that demodulates a digitally modulated received signal of an orthogonal polarization communication method using two mutually orthogonal polarizations having the same frequency; at least one variable coupler provided before or after the digital demodulator and capable of coupling a signal of one polarization to the other polarization and controlling the coupling amount by a control signal; A cross-polarization interference removal circuit comprising a control signal generator that is provided later and generates the control signal for the variable coupler based on the demodulated baseband signal, the cross-polarization interference canceling circuit detects an abnormality in the demodulated output of the digital demodulator. The apparatus includes at least one abnormality detection means for detecting an abnormality, and a reset means for setting at least one output of the variable coupler to a predetermined value based on the output of the abnormality detection means.
次に図面を参照しつつ本発明について詳細に説
明する。 Next, the present invention will be explained in detail with reference to the drawings.
第１図は本発明の第１の実施例のブロツク図
で、Ｖ、Ｈそれぞれの偏波の中間周波IF出力に
接続され波形等化を行うIF帯トランスバーサル
フイルタから成る適応型の波形等化器１，１′と、
Ｖ，ＨのIF出力を分岐しそれぞれ逆偏波の波形
等化器出力に結合しその結合量が制御可能なIF
帯トランスバーサルフイルタから成る可変結合器
２，２′と、波形等化器１，１′の出力に接続され
デイジタル信号を復調する同期検波方式のデイジ
タル復調器３，３′と、復調されたベースバンド
信号１００，１００′を基に波形等化器１，１′及
び可変結合器２，２′の制御信号１０１，１０
１′及び１０２，１０２′を発生する制御信号発生
器４と、デイジタル復調器１，１′の同期外れを
検出する同期外れ検出器５，５′とから構成され
ている。制御信号発生器４は制御信号発生部６と
４組のリセツト回路７，７′，８，８′とから構成
されており、制御信号発生部６はベースバンド帯
の入力信号１００，１００′を識別判定して送信
側の信号を推定し再生信号出力１０３，１０３′
を再生する再生機能と、入力信号１００，１０
０′と出力信号１０３，１０３′の差から誤差信号
を発生する誤差信号発生機能と、この誤差信号と
入力信号との相関を求めて各制御信号を逐次修正
する修正信号１０４，１０４′，１０５，１０
５′を発生する機能を備えている。リセツト回路
７，７′及び８，８′はそれぞれ修正信号１０４，
１０４′及び１０５，１０５′を積分して波形等化
器および可変結合器の制御信号を発生し、同期外
れ検出器５，５′の異常信号１０６，１０６′を受
けると制御信号をあらかじめ定めた初期値に設定
する回路である。波形等化器の修正信号１０４，
１０４′はそれぞれＶ，Ｈの同一偏波の入力信号
と誤差信号の相関を求めて発生され、可変結合器
の修正信号１０５，１０５′はそれぞれＶ、Ｈの
入力信号と逆偏波Ｈ、Ｖの誤差信号の相関を求め
て発生される。波形等化器１，１′および可変結
合器２，２′が例えば先行、中間、後続の３つの
タツプを有する３タツプのトランスバーサルフイ
ルタで構成されているときは、各制御信号１０
１，１０１′，１０２，１０２′はそれぞれ３つの
タツプのタツプ係数を制御する３つの制御信号を
含んでおり、先行、後続各タツプ制御信号はそれ
ぞれ誤差信号と相関をとる入力信号１００又は１
００′を１ビツト前後にシフトして求められる。
リセツト回路、７，７′はそれぞれ異常信号１０
６，１０６′によつて中間タツプのタツプ係数を
１に、先行、後続タツプのタツプ係数を０に設定
し、リセツト回路８，８′は異常信号１０６及び
１０６′によつてすべてのタツプ係数を０に設定
する。 FIG. 1 is a block diagram of the first embodiment of the present invention, which is an adaptive waveform equalization system consisting of an IF band transversal filter connected to the intermediate frequency IF output of each of the V and H polarizations and performing waveform equalization. Vessels 1, 1' and
An IF that branches the V and H IF outputs and couples them to the oppositely polarized waveform equalizer output, and the amount of coupling can be controlled.
Variable couplers 2, 2' consisting of band transversal filters, digital demodulators 3, 3' of a synchronous detection type connected to the outputs of waveform equalizers 1, 1' for demodulating digital signals, and a demodulated base. Control signals 101, 10 for waveform equalizers 1, 1' and variable couplers 2, 2' based on band signals 100, 100'
1' and 102, 102', and out-of-synchronization detectors 5, 5' that detect out-of-synchronization of the digital demodulators 1, 1'. The control signal generator 4 is composed of a control signal generator 6 and four sets of reset circuits 7, 7', 8, 8', and the control signal generator 6 receives baseband input signals 100, 100'. The identification is determined, the signal on the transmitting side is estimated, and the reproduced signal is output 103, 103'
and input signal 100, 10.
0' and output signals 103, 103', and correction signals 104, 104', 105 that sequentially correct each control signal by finding the correlation between this error signal and the input signal. ,10
It has the function of generating 5'. Reset circuits 7, 7' and 8, 8' respectively receive correction signals 104,
104' and 105, 105' are integrated to generate a control signal for the waveform equalizer and variable coupler, and upon receiving the abnormal signals 106, 106' from the out-of-synchronization detectors 5, 5', the control signal is determined in advance. This is a circuit that is set to an initial value. Waveform equalizer correction signal 104,
104' are generated by calculating the correlation between the input signals of the same polarization of V and H and the error signal, and the correction signals 105 and 105' of the variable coupler are generated by the input signals of V and H and the opposite polarization of H and V, respectively. It is generated by determining the correlation between the error signals. When the waveform equalizers 1, 1' and the variable couplers 2, 2' are composed of, for example, a 3-tap transversal filter having three taps, ie, leading, middle, and trailing taps, each control signal 10
1, 101', 102, and 102' each contain three control signals that control the tap coefficients of the three taps, and each of the leading and trailing tap control signals receives an input signal 100 or 1 that correlates with the error signal, respectively.
It is obtained by shifting 00' around 1 bit.
Reset circuit, 7, 7' is each abnormal signal 10
6, 106' sets the tap coefficient of the intermediate tap to 1, and the tap coefficients of the preceding and succeeding taps to 0, and the reset circuits 8, 8' reset all the tap coefficients by the abnormal signals 106 and 106'. Set to 0.
上述した第１図の回路は、同期外れ検出器５，
５′と各リセツト回路の異常信号１０６，１０
６′によるリセツト機能とを除けば従来型の交差
偏波干渉除去回路である。すなわち、波形等化器
および可変結合器にIF帯のトランスバーサルフ
イルタを用いているが特開昭55−133156号公報記
載のものと同じ技術思想によるものであつて、そ
の制御方法は全く同じであり、トランスバーサル
フイルタを用いた適応型等化器の制御方法として
知られているZF（ゼロフオーシング）法の制御ア
ルゴリズムを適用したものであつて、実際の制御
回路はすべてデイジタル処理するよう構成されて
いる。復調されたベースバンド信号を用いたこの
制御アルゴリズムを、中間周波数cを必ずしも変
調周波数sの整数倍に選定できない一般のマイク
ロ波帯通信において、IF帯トランスバーサルフ
イルタを用いた適応型波形等化器に適用する方法
が特願昭56−215217号に提案されており、この方
法はIF帯トランスバーサルフイルタを用いた交
差偏波干渉除去回路にも同様に適用することがで
きる。この方法は本特許と直接関係を有するもの
でないので省略するが、必要あれば前記特願昭56
−215271号を参照されたい。なお、第１図におい
てＶ，Ｈ偏波の両入力は、同一ビツトレートで変
調された同一またはほぼ同一周波数の無線信号を
同じ局部発振器によつて中間周波数に変換した信
号である。 The circuit shown in FIG. 1 described above includes an out-of-synchronization detector 5,
5' and abnormal signals 106 and 10 of each reset circuit.
This is a conventional cross-polarization interference canceling circuit except for the reset function provided by 6'. That is, although an IF band transversal filter is used in the waveform equalizer and variable coupler, it is based on the same technical idea as that described in Japanese Patent Application Laid-Open No. 133156/1982, and the control method is exactly the same. The ZF (zero-focusing) control algorithm, which is known as a control method for adaptive equalizers using transversal filters, is applied, and the actual control circuit is configured to perform all digital processing. has been done. This control algorithm using a demodulated baseband signal is applied to an adaptive waveform equalizer using an IF band transversal filter in general microwave band communication where the intermediate frequency c cannot necessarily be selected as an integral multiple of the modulation frequency s. A method applied to this is proposed in Japanese Patent Application No. 56-215217, and this method can be similarly applied to a cross-polarization interference removal circuit using an IF band transversal filter. This method is not directly related to this patent, so it will be omitted, but if necessary,
Please refer to No.-215271. In FIG. 1, both the V and H polarization inputs are signals obtained by converting radio signals of the same or substantially the same frequency modulated at the same bit rate to an intermediate frequency by the same local oscillator.
いま、Ｖ偏波のデイジタル復調器３の搬送波同
期が外れたとすると、復調出力１００には、たと
えビツト同期がＨ偏波の復調器出力によつて保た
れたとしても、もはやＶ偏波で送信されたベース
バンド信号情報を含まない。従つて、信号１００
とＨ偏波の信号１００′から得られる誤差信号と
の相関を求めてＨ偏波に含まれるＶ偏波の干渉を
最少に制御する可変結合器２の制御ループは正常
に動作せず、制御信号１０２は不定となつて、た
またま修正信号１０５として現れる無意味なじよ
う乱情報のままに変動することとなり、可変結合
器２の出力１０７にはＨ偏波の干渉を相殺するど
ころか、逆に干渉を増大させる信号が出力される
可能性があり、Ｖ偏波の再生出力１０３′の符号
誤りを大きくする原因となる。同様に、Ｖ偏波の
復調された信号１００から得られる誤差信号とＨ
偏波の信号１００′との相関を求めて制御される
可変結合器２′の出力１０７′も不安となり、Ｖ偏
波への干渉を増大させデイジタル復調器３の搬送
波同期の回復および可変結合器２′の正常動作へ
の復帰を遅らせる原因となる。第１図に示す本発
明の第１の実施例の回路では、同期外れ検出器５
によつて同期外れを検出し異常信号１０６によつ
てリセツト回路８，８′の積分器を放電し、トラ
ンスバーサルフイルムの各タツプ係数を０として
可変結合器２，２′の出力１０７，１０７′がすべ
て０となるよう構成されているので上述した欠点
を除くことができる。なお、波形等化器１は従来
の波形等化器で既に行われているように中間タツ
プのタツプ係数が１となり、先行および後続のタ
ツプ係数が０となるよう制御されている。Ｈ偏波
の搬送波同期外れに対しても同様であり、可変結
合器２，２′が異常信号１０６′によりリセツトさ
れる。 Now, if the carrier synchronization of the V-polarized digital demodulator 3 is lost, the demodulated output 100 will no longer be transmitted in the V-polarized state, even if bit synchronization is maintained by the H-polarized demodulator output. Contains no baseband signal information. Therefore, the signal 100
The control loop of the variable coupler 2, which minimizes the interference of the V polarization included in the H polarization by determining the correlation between the error signal obtained from the H polarization signal 100', does not operate normally, and the control loop The signal 102 becomes unstable and fluctuates as meaningless disturbance information that happens to appear as the corrected signal 105, and the output 107 of the variable coupler 2 does not cancel out the interference of the H polarized wave, but on the contrary causes interference. There is a possibility that a signal that increases the output voltage is output, which causes an increase in the code error of the V-polarized reproduced output 103'. Similarly, the error signal obtained from the V-polarized demodulated signal 100 and the H
The output 107' of the variable coupler 2', which is controlled by determining the correlation with the polarized signal 100', also becomes unstable, increasing the interference to the V-polarized wave, and causing the recovery of carrier synchronization of the digital demodulator 3 and the variable coupler. This causes a delay in the return to normal operation of 2'. In the circuit of the first embodiment of the present invention shown in FIG.
The out-of-synchronization is detected by the error signal 106, and the integrators of the reset circuits 8, 8' are discharged, and each tap coefficient of the transversal film is set to 0, and the outputs 107, 107' of the variable couplers 2, 2' are Since the configuration is such that all of the values are 0, the above-mentioned drawbacks can be eliminated. The waveform equalizer 1 is controlled so that the intermediate tap has a tap coefficient of 1 and the preceding and succeeding tap coefficients have a value of 0, as is already done in conventional waveform equalizers. The same applies to carrier synchronization loss for H polarized waves, and the variable couplers 2 and 2' are reset by the abnormal signal 106'.
第２図は第１図のリセツト回路７，７′，８，
８′の各タツプを制御する要素回路の一実施例の
ブロツク図で、AND／NANDゲート６１および
６３、ANDゲート６２、ORゲート６４、積分回
路６５レベルシフト回路６６で構成され、異常信
号１０６，１０６′が“１”のとき（同期状態）
修正信号１０４，１０４′，１０５，１０５′は積
分回路６５で通常の積分が行われるが、異常信号
が“０”のとき積分回路６５の出力を放電し
AND／NANDゲート６３のしきい値に固定され
るようになつている。レベルシフト回路６６は、
このしきい値と異る制御信号１０１，１０１′，
１０２，１０２′の初期値を与えるために用いら
れる。この回路の詳細は特願昭56−215271号に述
べられているので参照されたい。又、同期外れ検
出回路としては、特開昭48−17661号公報記載の
各回路を使用することができる。 FIG. 2 shows the reset circuits 7, 7', 8, and
This is a block diagram of an embodiment of an element circuit for controlling each tap of 8', which is composed of AND/NAND gates 61 and 63, an AND gate 62, an OR gate 64, an integrating circuit 65, a level shift circuit 66, and an abnormal signal 106, When 106' is "1" (synchronized state)
The correction signals 104, 104', 105, and 105' are normally integrated by the integrating circuit 65, but when the abnormal signal is "0", the output of the integrating circuit 65 is discharged.
It is designed to be fixed to the threshold value of AND/NAND gate 63. The level shift circuit 66 is
Control signals 101, 101' different from this threshold value,
It is used to give initial values of 102 and 102'. Details of this circuit are described in Japanese Patent Application No. 56-215271, so please refer to it. Further, as the out-of-synchronization detection circuit, various circuits described in Japanese Patent Application Laid-Open No. 17661/1988 can be used.
第３図は本発明の第２の実施例のブロツク図で
あり、ベースバンド帯のトランスバーサルフイル
タを用いた実施例である。各偏波の信号を復調す
るデイジタル復調器１３，１３′の後に、ベース
バンド帯のトランスバーサルフイルタから成る波
形等化器１１，１１′と可変結合器１２，１２′と
が接続され、第１図と同様なリセツト機能を有す
る制御信号発生器１４により制御される。この第
３図の回路の動作原理は、デイジタル復調器と可
変結合器および波形等化器と位置が入れ替わつて
いるが第１図の場合と何ら変りなく、本発明によ
り第１図の場合と同等の効果が得られる。 FIG. 3 is a block diagram of a second embodiment of the present invention, which is an embodiment using a baseband transversal filter. After the digital demodulators 13, 13' that demodulate the signals of each polarization, waveform equalizers 11, 11' consisting of baseband transversal filters and variable couplers 12, 12' are connected. It is controlled by a control signal generator 14 having a reset function similar to that shown. The operating principle of the circuit shown in Fig. 3 is the same as that shown in Fig. 1, although the positions of the digital demodulator, variable coupler, and waveform equalizer are switched. The same effect can be obtained.
第４図は本発明の第３の実施例のブロツク図で
あり、干渉性のフエージングが少ない衛星通信方
式を対象とし、摂動法による制御（特願昭56−
055530）を用いた実施例である。第４図におい
て、可変結合器２２，２２′は１つの可変重み付
け回路から構成され、Ｖ偏波の干渉を除去する可
変結合器２２′の制御信号１２２′はＨ偏波の復調
出力１２０′とは無関係で、Ｖ偏波の復調出力１
２０と制御信号１２２′に重畳して送出される摂
動信号とから制御信号発生部２６で発生される。
同様にＨ偏波の干渉を除去する可変結合器２２の
制御信号１２２は、制御信号発生部２６′でＶ偏
波の復調出力１２０と無関係に発生される。従つ
て、Ｖ偏波の復調器２３の同期外れはＨ偏波の干
渉を増大させる恐れは無く、同期外れ検出器２５
の出力１２６は同期回復時の正常状態復帰の目的
で制御信号発生部２６に加えられ制御信号１２
２′を初期値にリセツトするよう構成されている。
同様にＨ偏波の同期外れ検出器２３′の出力１２
６′はＨ偏波側の制御信号発生部２６′に加えられ
制御信号１２２をリセツトする。なお、１２３，
１２３′は再生出力信号である。 FIG. 4 is a block diagram of a third embodiment of the present invention, which is aimed at a satellite communication system with less interferential fading, and is controlled by the perturbation method (Japanese Patent Application No.
This is an example using 055530). In FIG. 4, the variable couplers 22 and 22' are composed of one variable weighting circuit, and the control signal 122' of the variable coupler 22' that removes the interference of the V polarization is the demodulated output 120' of the H polarization. is irrelevant, and the demodulated output of V polarization is 1
20 and a perturbation signal sent out superimposed on the control signal 122'.
Similarly, a control signal 122 for the variable coupler 22 that removes interference from the H polarization is generated by the control signal generator 26' independently of the demodulated output 120 for the V polarization. Therefore, there is no fear that the desynchronization of the demodulator 23 of the V polarization will increase the interference of the H polarization, and the desynchronization detector 25
The output 126 of
2' to the initial value.
Similarly, the output 12 of the H polarization out-of-synchronization detector 23'
6' is applied to the control signal generator 26' on the H polarization side to reset the control signal 122. In addition, 123,
123' is a reproduction output signal.
第５図は第４図の制御信号発生部２６，２６′
の一実施例のブロツク図で、復調信号１２０を識
別再生し誤差信号を検出する信号識別・誤差検出
器７０と、制御信号１２２′に重畳される摂動信
号を発生する発振器７１と、誤差信号と摂動信号
との相関を求める相関器７２と、相関器７２の出
力を積分するリセツト機能を有する積分器７３
と、その出力を反転し制御信号を作成するインバ
ータ７４と、制御信号に摂動信号を重畳する加算
器７５と、重畳される摂動信号の大きさを制御す
る減衰器７６と、減衰器７６を制御する誤差信号
の平均値を求める低域フイルタ７７とから構成さ
れている。この回路によれば可変結合器２２，２
２′の出力に摂動が加えられ、誤差信号に含まれ
る摂動成分を相関器７２で検出して逐次制御の方
向を決定し、相手偏波の復調信号情報を用いずに
交差偏波干渉波除去ができる。なお、動作原理お
よび回路の詳細については前記特願昭56−055530
を参照されたい。 FIG. 5 shows the control signal generators 26, 26' of FIG.
The block diagram of one embodiment shows a signal identification/error detector 70 that identifies and reproduces a demodulated signal 120 and detects an error signal, an oscillator 71 that generates a perturbation signal to be superimposed on a control signal 122', and an error signal. A correlator 72 that determines the correlation with the perturbation signal, and an integrator 73 that has a reset function that integrates the output of the correlator 72.
, an inverter 74 that inverts its output to create a control signal, an adder 75 that superimposes a perturbation signal on the control signal, an attenuator 76 that controls the magnitude of the superimposed perturbation signal, and an attenuator 76 that controls the attenuator 76. and a low-pass filter 77 for finding the average value of the error signals. According to this circuit, variable couplers 22, 2
A perturbation is added to the output of 2', and the correlator 72 detects the perturbation component included in the error signal to determine the direction of sequential control, and removes cross-polarization interference waves without using demodulated signal information of the other polarization. I can do it. For details of the operating principle and circuit, please refer to the above-mentioned patent application No. 56-055530.
Please refer to
上述した第１図および第３図の実施例では可変
結合器は波形等化器の前から分岐しているが、波
形等化器の後で分岐し主偏波側に遅延回路を挿入
して時間合わせを行う交差偏波干渉除去回路に適
用しても同様な効果が得られる。又、一方の偏波
の同期外れ検出器の異常信号によつて、両方の可
変結合器をリセツトする様に構成されているが、
異常の発生した偏波側から正常な相手偏波側に与
える影響のみを重視し、復帰促進のためのリセツ
トを省略しても相応の効果が得られる。なお、制
御信号の発生方法はZF法アルゴリズムによると
したが第３図のベースバンド帯の場合は、ZF法
と共に公知のME法（自乗平均等化法）のアルゴ
リズムを用いても同様な効果が期待できる。又、
第４図の実施例では可変結合器を１つの可変重み
付け回路から成るものとしたが、第１図、第３図
と同じトランスバーサルフイルタで構成すること
もできるし、波形等化器を備えても同様な効果が
ある。更に、上述の各実施例はすべてデイジタル
復調器の同期外れを検出してリセツトを行うよう
構成されているが、デイジタル復調器の出力に符
号誤り検出器を設け、送信側から周期的に送られ
てくる既知の符号の誤りを検出することによつて
復調出力の異常を検出し、この誤りが一定の値を
越えて劣化したときに可変結合器をリセツトする
ようにしてもよい。この場合には遅延検波型のデ
イジタル復調器を使用することができる。又、リ
セツト方式も第２図の実施例の回路に限らず、初
期値設定用電源と切換回路を用いたより一般的な
回路を使用することもでき、設定値も必ずしも結
合０でなくてもよい。なお、これまでの説明は受
信局が復調されたＶ，Ｈ両偏波の信号を利用する
ものと考えたが、衛星通信の地上局等では一局で
必ずしも両偏波の信号を使用しない場合も考えら
れ、上述の実施例の構成の一部を省略することが
できる。例えば、第４図において、Ｖ偏波のみを
使用する場合は、可変結合器２２、デイジタル復
調器２３′同期外れ検出器２５′及び制御信号発生
部２６′は省略可能であり、これを省略しても本
発明の効果は発揮される。又、各偏波が直交変調
された場合でも本発明は適用が可能である。 In the embodiments of FIGS. 1 and 3 described above, the variable coupler is branched before the waveform equalizer, but it is branched after the waveform equalizer and a delay circuit is inserted on the main polarization side. A similar effect can be obtained even when applied to a cross-polarization interference removal circuit that performs time adjustment. Also, it is configured so that both variable couplers are reset by an abnormal signal from the out-of-synchronization detector of one polarization.
Even if emphasis is placed only on the influence of the polarized wave side where the abnormality has occurred on the normal polarized wave side of the other party, and the reset for promoting recovery is omitted, a corresponding effect can be obtained. Although the control signal generation method is based on the ZF method algorithm, in the case of the baseband band shown in Figure 3, the same effect can be obtained by using the well-known ME method (root mean square equalization method) algorithm in addition to the ZF method. You can expect it. or,
In the embodiment shown in FIG. 4, the variable coupler is made up of one variable weighting circuit, but it can also be made up of the same transversal filter as in FIGS. 1 and 3, or it can be made up of a waveform equalizer. has a similar effect. Furthermore, although all of the above-mentioned embodiments are configured to detect synchronization loss of the digital demodulator and perform reset, a code error detector is provided at the output of the digital demodulator, and a code error detector is provided at the output of the digital demodulator to detect the synchronization signal periodically sent from the transmitting side. It is also possible to detect an abnormality in the demodulated output by detecting an error in a known code that is coming, and to reset the variable coupler when this error deteriorates beyond a certain value. In this case, a differential detection type digital demodulator can be used. Furthermore, the reset method is not limited to the circuit of the embodiment shown in Fig. 2, but a more general circuit using an initial value setting power supply and a switching circuit can also be used, and the set value does not necessarily have to be 0. . In addition, in the explanation so far, it has been assumed that the receiving station uses demodulated signals of both V and H polarizations, but in the case of satellite communication ground stations, etc., there are cases where a single station does not necessarily use signals of both polarizations. It is also possible to omit part of the configuration of the above-described embodiment. For example, in FIG. 4, when only V polarization is used, the variable coupler 22, the digital demodulator 23', the out-of-sync detector 25', and the control signal generator 26' can be omitted. However, the effects of the present invention can still be achieved. Furthermore, the present invention is applicable even when each polarized wave is orthogonally modulated.
以上詳細に説明したように、本発明の交差偏波
干渉除去回路によれば、直交する２つの偏波を用
いてデイジタル通信を行う直交偏波通信方式にお
いて、一方の偏波の復調器の復調出力に異常が発
生したとき、少なくとも他方の偏波の復調出力を
劣化させないか又は異常が回復したときの正常状
態への復帰を早めるという効果がある。 As explained in detail above, according to the cross-polarization interference cancellation circuit of the present invention, in an orthogonal polarization communication system that performs digital communication using two orthogonal polarizations, the demodulator of one polarization performs demodulation. When an abnormality occurs in the output, there is an effect that at least the demodulated output of the other polarized wave is not degraded or the return to the normal state is accelerated when the abnormality is recovered.
第１図は本発明の第１の実施例のブロツク図、
第２図は第１図のリセツト回路の一実施例のブロ
ツク図、第３図は本発明の第２の実施例のブロツ
ク図、第４図は本発明の第３の実施例のブロツク
図、第５図は第４図の制御信号発生部の一実施例
のブロツク図である。
１，１′，１１，１１′……波形等化器、２，
２′，１２，１２′，２２，２２′……可変結合器、
３，３′，１３，１３′，２３，２３′……デイジ
タル復調器、４，１４……制御信号発生器、５，
５′，１５，１５′，２５，２５′……同期外れ検
出器、６，２６，２６′……制御信号発生部、７，
７′，８，８′……リセツト回路、６１，６３……
AND／NANDゲート、６２……ANDゲート、
６４……ORゲート、６５……積分回路、６６…
…レベルシフト回路、７０……信号識別・誤差検
出器、７１……発振器、７２……相関器、７３…
…積分器、７４……インバータ、７５……加算
器、７６……減衰器、７７……低域フイルタ。
FIG. 1 is a block diagram of a first embodiment of the present invention;
2 is a block diagram of one embodiment of the reset circuit of FIG. 1, FIG. 3 is a block diagram of a second embodiment of the present invention, and FIG. 4 is a block diagram of a third embodiment of the present invention. FIG. 5 is a block diagram of one embodiment of the control signal generating section of FIG. 4. 1, 1', 11, 11'... waveform equalizer, 2,
2', 12, 12', 22, 22'... variable coupler,
3, 3', 13, 13', 23, 23'...Digital demodulator, 4, 14...Control signal generator, 5,
5', 15, 15', 25, 25'... Out-of-synchronization detector, 6, 26, 26'... Control signal generator, 7,
7', 8, 8'...Reset circuit, 61, 63...
AND/NAND gate, 62...AND gate,
64...OR gate, 65...integrator circuit, 66...
... Level shift circuit, 70 ... Signal discrimination/error detector, 71 ... Oscillator, 72 ... Correlator, 73 ...
...integrator, 74...inverter, 75...adder, 76...attenuator, 77...low-pass filter.
Claims (1)
用する直交偏波通信方式のデイジタル変調された
受信信号を復調する少なくとも１つのデイジタル
復調器と、このデイジタル復調器の前または後に
設けられ一方の偏波の信号を他方の偏波に結合し
その結合量を制御信号によつて制御できる少なく
とも１つの可変結合器と、前記デイジタル復調器
および前記可変結合器の後に設けられ復調された
ベースバンド信号を基にして前記可変結合器の前
記制御信号を発生する制御信号発生器とを備えた
交差偏波干渉除去回路において、前記デイジタル
復調器の復調出力の異常を検出する少なくとも１
つの異常検出手段と、この異常検出手段の出力に
より前記可変結合器の少なくとも１つの出力をあ
らかじめ定めた値に設定するリセツト手段とを有
することを特徴とする交差偏波干渉除去回路。1 At least one digital demodulator that demodulates a digitally modulated reception signal of an orthogonal polarization communication system that uses two mutually orthogonal polarized waves at the same frequency, and a at least one variable coupler capable of coupling one wave signal to the other polarized wave and controlling the coupling amount by a control signal; a control signal generator that generates the control signal of the variable coupler based on the cross-polarization interference canceling circuit, at least one
1. A cross-polarization interference removal circuit comprising: one abnormality detection means; and a reset means for setting at least one output of the variable coupler to a predetermined value based on the output of the abnormality detection means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57187713A JPS5977734A (en) | 1982-10-26 | 1982-10-26 | Circuit for eliminating interference of cross polarization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57187713A JPS5977734A (en) | 1982-10-26 | 1982-10-26 | Circuit for eliminating interference of cross polarization |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5977734A JPS5977734A (en) | 1984-05-04 |
| JPS6412136B2 true JPS6412136B2 (en) | 1989-02-28 |
Family
ID=16210864
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57187713A Granted JPS5977734A (en) | 1982-10-26 | 1982-10-26 | Circuit for eliminating interference of cross polarization |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5977734A (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4688235A (en) * | 1984-11-30 | 1987-08-18 | Nec Corporation | Cross-polarization interference canceller |
| JPS63199547A (en) * | 1987-02-13 | 1988-08-18 | Nec Corp | Radio transmission system |
| JPS6422130A (en) * | 1987-07-16 | 1989-01-25 | Nec Corp | System for resetting intercrossing polarized wave interference removing device |
| JPH0214633A (en) * | 1988-06-30 | 1990-01-18 | Nec Corp | Both-polarized wave digital transmission system |
| JPH0282831A (en) * | 1988-09-20 | 1990-03-23 | Fujitsu Ltd | Inter-axial ratio compensation system |
| JPH02295242A (en) * | 1989-05-09 | 1990-12-06 | Nec Corp | Cross polalization interference eliminating circuit |
| JP2591155B2 (en) * | 1989-05-09 | 1997-03-19 | 日本電気株式会社 | Polarization interference canceler |
| JP2694257B2 (en) * | 1989-06-12 | 1997-12-24 | 日本電信電話株式会社 | Cross polarization interference compensation method |
| JPH0683178B2 (en) * | 1989-08-25 | 1994-10-19 | 日本電気株式会社 | Cross polarization interference canceller |
| JP2591213B2 (en) * | 1990-01-25 | 1997-03-19 | 日本電気株式会社 | Cross polarization interference cancellation circuit |
| JPH0653929A (en) * | 1992-07-31 | 1994-02-25 | Nec Corp | Orthogonal polarization communication system |
-
1982
- 1982-10-26 JP JP57187713A patent/JPS5977734A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5977734A (en) | 1984-05-04 |
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