JPS623622B2 - - Google Patents
Info
- Publication number
- JPS623622B2 JPS623622B2 JP56180165A JP18016581A JPS623622B2 JP S623622 B2 JPS623622 B2 JP S623622B2 JP 56180165 A JP56180165 A JP 56180165A JP 18016581 A JP18016581 A JP 18016581A JP S623622 B2 JPS623622 B2 JP S623622B2
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- bandpass filter
- intermediate frequency
- received wave
- output
- 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
- 230000015572 biosynthetic process Effects 0.000 claims description 3
- 238000003786 synthesis reaction Methods 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000010355 oscillation Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
- H04B7/0837—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using pre-detection combining
- H04B7/084—Equal gain combining, only phase adjustments
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Radio Transmission System (AREA)
Description
【発明の詳細な説明】
本発明はマイクロ波FM伝送のスペースダイバ
ーシチ・ベースバンド合成受信機に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a space diversity baseband combining receiver for microwave FM transmission.
スペースダイバーシチ・ベースバンド合成受信
方式は回線の信頼度を高め、同時に信号対雑音比
をも高める伝送方式の一つである。 The space diversity baseband combining reception method is one of the transmission methods that increases the reliability of the line and at the same time increases the signal-to-noise ratio.
これまでの方法によると、同一の受信機を２台
用いベーススバンドの出力で同相合成をしていた
ため、単独受信構成に比し熱雑音は改善される
が、歪雑音の改善は全く期待できなかつた。 According to the previous method, two identical receivers were used and in-phase synthesis was performed using the baseband output, which improved thermal noise compared to a single receiver configuration, but no improvement in distortion noise could be expected. Nakatsuta.
受信機の歪みの要因としてはRF系やIF系のろ
波器による群遅延特性と微分利得特性および復調
器（ベースバンド系増幅器を含む）の非直線性、
群遅延特性、微分利得特性であり、歪みの中でも
二次歪が支配的である。 The causes of receiver distortion are the group delay characteristics and differential gain characteristics of the RF and IF filters, the nonlinearity of the demodulator (including the baseband amplifier),
These are group delay characteristics and differential gain characteristics, and among distortions, second-order distortion is dominant.
工場で複数の受信機を同時期に製作した場合、
電気的特性は極めて類似しており、当然二次歪も
同一特性を有している。 If multiple receivers are manufactured at the same time at the factory,
The electrical characteristics are extremely similar, and naturally the second-order distortion also has the same characteristics.
本発明はこのように同一の特性を有するものを
並列に合成するベースバンド合成受信機になした
もので、その目的は二次歪の低減化を図つたスペ
ースダイバーシチ・ベースバンド合成受信機を提
供することにある。 The present invention is a baseband combining receiver that combines components having the same characteristics in parallel, and its purpose is to provide a space diversity baseband combining receiver that reduces second-order distortion. It's about doing.
前記目的を達成するために本発明によるスペー
スダイバーシチ・ベースバンド合成受信機は、第
１受信波の第１バンドパスフイルタと、第２の受
信波の第２バンドパスフイルタと、前記第１バン
ドパスフイルタから出力される第１受信波周波数
を中間周波数に変換する第１周波数変換器と、前
記第２バンドパスフイルタから出力される第２受
信波周波数を中間周波数に変換する第２周波数変
換器と、前記第１周波数変換器に接続され、下記
(1)式の条件を満たす周波数L1を出力する第１
局部発振器と、前記第２周波数変換器に接続さ
れ、下記(2)式の条件を満たす周波数L2を出力
する第２局部発振器と、前記第１周波数変換器か
ら出力される中間周波数の第１中間周波バンドパ
スフイルタと、前記第２周波数変換器から出力さ
れる中間周波数の第２中間周波バンドパスフイル
タと、前記第１中間周波バンドパスフイルタ出力
をベースバンド信号に復調する第1FM復調器
と、周波数偏移に対して前記第1FM復調器と同
一のベースバンド出力極性を有し、前記第２中間
周波バンドパスフイルタ出力をベースバンド信号
に復調する第2FM復調器と、前記第１、第2FM
復調器出力を合成する逆相ハイブリツドとから構
成してある。 In order to achieve the above object, a space diversity baseband combining receiver according to the present invention includes a first bandpass filter for a first received wave, a second bandpass filter for a second received wave, and a first bandpass filter for a first received wave. a first frequency converter that converts a first received wave frequency output from the filter into an intermediate frequency; and a second frequency converter that converts a second received wave frequency output from the second bandpass filter into an intermediate frequency. , connected to the first frequency converter,
The first one outputs the frequency L 1 that satisfies the condition of equation (1).
a local oscillator, a second local oscillator that is connected to the second frequency converter and outputs a frequency L2 that satisfies the condition of equation (2) below, and a first intermediate frequency output from the first frequency converter; an intermediate frequency bandpass filter, a second intermediate frequency bandpass filter of the intermediate frequency output from the second frequency converter, and a first FM demodulator that demodulates the output of the first intermediate frequency bandpass filter into a baseband signal. , a second FM demodulator having the same baseband output polarity with respect to frequency shift as the first FM demodulator and demodulating the output of the second intermediate frequency bandpass filter into a baseband signal; 2FM
It consists of an anti-phase hybrid that combines demodulator outputs.
L1＝Ｒ＋Ｉ ……(1)
L2＝Ｒ−Ｉ ……(2)
ただしＲは第１、第２受信波周波数
Ｉは中間周波数
上記構成によれば、歪は低減され本発明の目的
は完全に達成される。 L 1 = R + I ... (1) L 2 = R - I ... (2) where R is the first and second received wave frequency I is the intermediate frequency According to the above configuration, distortion is reduced and the object of the present invention is fully achieved.
以下、図面を参照して本発明をさらに詳しく説
明する。 Hereinafter, the present invention will be explained in more detail with reference to the drawings.
第１図は本発明によるスペースダイバーシチ・
ベースバンド合成受信機の一実施例を示す回路ブ
ロツク図である。入力１ａおよび入力１ｂはそれ
ぞれ図示しない空中線系に接続される受信機の入
力端子である。今、受信波の周波数をＲとし、
入力端子１ａに入力される受信波を第１受信波、
入力端子１ｂに入力される受信波を第２受信波と
すると、第１受信波はRF系の第１バンドパスフ
イルタ（BPF）２ａを通つて第１周波数変換器３
ａに導びかれ、同様に第２受信波もRF系の第２
バンドパスフイルタ２ｂを通つて第２周波数変換
器２ｂに導びかれる。第１局部発振器４ａは、中
間周波数の中心周波数をＩ、受信周波数をＲ
とすると、その発振周波数L1は下記(3)式を満
たすように設定されている。 Figure 1 shows the space diversity system according to the present invention.
1 is a circuit block diagram showing one embodiment of a baseband combining receiver. FIG. Input 1a and input 1b are input terminals of a receiver connected to an antenna system (not shown), respectively. Now, let the frequency of the received wave be R,
The received wave input to the input terminal 1a is called a first received wave,
If the received wave input to the input terminal 1b is the second received wave, the first received wave passes through the first band pass filter (BPF) 2a of the RF system and is then sent to the first frequency converter 3.
Similarly, the second received wave is also guided by the second wave of the RF system.
The signal is guided to a second frequency converter 2b through a bandpass filter 2b. The first local oscillator 4a sets the center frequency of the intermediate frequency to I and the reception frequency to R.
Then, the oscillation frequency L 1 is set to satisfy the following equation (3).
Ｒ＝L1−Ｉ ……(3)
また、第２局部発振器４ｂもその発振周波数
L2は下記(4)式を満たすように設定されている。 R=L 1 −I ...(3) Also, the second local oscillator 4b also has its oscillation frequency
L 2 is set to satisfy the following equation (4).
Ｒ＝L2＋Ｉ ……(4)
したがつて、第１、第２周波数変換器３ａ，３
ｂからそれぞれ出力される中間周波数Ｉの周波
数偏移方向は経路９ａと９ｂでは逆になり、これ
以後の回路で発生する二次歪は２系統の歪率が同
一であれば180゜位相がずれることになる。経路
９ａを経由した信号は第１中間周波バンドパスフ
イルタ（IF BPF）５ａを通り復調器６ａによつ
てベースバンド信号に変換される。同様に経路９
ｂを経由した信号も第２中間周波バンドパスフイ
ルタ（IF BPF）５ｂを通り復調器６ｂに導びか
れ、ベースバンド信号に復調される。 R=L 2 +I ...(4) Therefore, the first and second frequency converters 3a, 3
The frequency deviation direction of the intermediate frequency I output from each path is opposite in paths 9a and 9b, and the second-order distortion generated in the subsequent circuits will be out of phase by 180° if the distortion factors of the two systems are the same. It turns out. The signal via the path 9a passes through a first intermediate frequency bandpass filter (IF BPF) 5a and is converted into a baseband signal by a demodulator 6a. Similarly route 9
The signal that has passed through b also passes through a second intermediate frequency bandpass filter (IF BPF) 5b, is guided to a demodulator 6b, and is demodulated into a baseband signal.
第１、第２復調器６ａと６ｂは中間周波の周波
数偏移に対しそれぞれ同一の極性特性を有してい
るので、出力信号１０ａと１０ｂは極性が逆とな
つて現われる。これら信号１０ａと１０ｂはこの
後逆相ハイブリツド７によつて合成される。した
がつて信号成分は、同相に、二次歪成分は逆相に
合成され出力端子８よりベースバンド出力が取り
出される。 Since the first and second demodulators 6a and 6b each have the same polarity characteristics with respect to the frequency shift of the intermediate frequency, the output signals 10a and 10b appear with opposite polarities. These signals 10a and 10b are then combined by an anti-phase hybrid 7. Therefore, the signal components are combined in-phase, the second-order distortion components are combined in anti-phase, and a baseband output is taken out from the output terminal 8.
従来回路では、周波数変換器の局部発振周波数
を同一に選んでいたため、第１図におけるIF
BPF以後で発生する二次歪は同相に合成され、信
号対歪比は改善されなかつた。 In the conventional circuit, the local oscillation frequencies of the frequency converters were selected to be the same, so the IF in Figure 1
The second-order distortion generated after the BPF was combined into the same phase, and the signal-to-distortion ratio was not improved.
しかし、本発明によれば、二次歪率が２つの系
統で同一ならば無限に改善される可能性を有して
いる。 However, according to the present invention, if the second-order distortion factors are the same in the two systems, there is a possibility of infinite improvement.
以上、詳しく説明したように本発明によれば二
次歪を低減したマイクロ波FM伝送のスペースダ
イバーシチ・ベースバンド合成受信機を提供でき
る。 As described in detail above, according to the present invention, it is possible to provide a space diversity baseband synthesis receiver for microwave FM transmission in which second-order distortion is reduced.
第１図は本発明によるスペースダイバーシチ・
ベースバンド合成受信機の一実施例を示す回路図
である。
１ａ……第１受信波入力端子、１ｂ……第２受
信波入力端子、２ａ……第１マイクロ波BPF、２
ｂ……第２マイクロ波BPF、３ａ……第１受信周
波数変換器、３ｂ……第２受信周波数変換器、４
ａ……第１局部発振器、４ｂ……第２局部発振
器、５ａ……第1IF BPF、５ｂ……第2IF
BPF、６ａ……第1FM復調器、６ｂ……第2FM
復調器、７……逆相ハイブリツド、８……ベース
バンド出力端子。
Figure 1 shows the space diversity system according to the present invention.
FIG. 2 is a circuit diagram showing an example of a baseband combining receiver. 1a...First received wave input terminal, 1b...Second received wave input terminal, 2a...First microwave BPF, 2
b...Second microwave BPF, 3a...First reception frequency converter, 3b...Second reception frequency converter, 4
a...first local oscillator, 4b...second local oscillator, 5a...first IF BPF, 5b...second IF
BPF, 6a...1st FM demodulator, 6b...2nd FM
Demodulator, 7...Negative phase hybrid, 8...Baseband output terminal.
Claims (1)
２の受信波の第２バンドパスフイルタと、前記第
１バンドパスフイルタから出力される第１受信波
周波数を中間周波数に変換する第１周波数変換器
と、前記第２バンドパスフイルタから出力される
第２受信波周波数を中間周波数に変換する第２周
波数変換器と、前記第１周波数変換器に接続さ
れ、下記(1)式の条件を満たす周波数L1を出力
する第１局部発振器と、前記第２周波数変換器に
接続され、下記(2)式の条件を満たす周波数L2
を出力する第２局部発振器と、前記第１周波数変
換器から出力される中間周波数の第１中間周波バ
ンドパスフイルタと、前記第２周波数変換器から
出力される中間周波数の第２中間周波バンドパス
フイルタと、前記第１中間周波バンドパスフイル
タ出力をベースバンド信号に復調する第1FM復
調器と、周波数偏移に対して前記第1FM復調器
と同一のベースバンド出力極性を有し、前記第２
中間周波バンドパスフイルタ出力をベースバンド
信号に復調する第2FM復調器と、前記第１、第
2FM復調器出力を合成する逆相ハイブリツドと
から構成したスペースダイバーシチ・ベースバン
ド合成受信機。 L1＝Ｒ＋Ｉ ……(1) L2＝Ｒ−Ｉ ……(2) ただしＲは第１、第２受信波周波数 Ｉは中間周波数[Claims] 1. A first bandpass filter for a first received wave, a second bandpass filter for a second received wave, and a first received wave frequency output from the first bandpass filter as an intermediate frequency. a second frequency converter that converts the second received wave frequency output from the second bandpass filter into an intermediate frequency; A first local oscillator that outputs a frequency L 1 that satisfies the condition of formula (1), and a frequency L 2 that is connected to the second frequency converter and satisfies the condition of formula (2) below.
a second local oscillator that outputs a second local oscillator, a first intermediate frequency bandpass filter of an intermediate frequency output from the first frequency converter, and a second intermediate frequency bandpass filter of an intermediate frequency output from the second frequency converter. a first FM demodulator for demodulating the first intermediate frequency bandpass filter output into a baseband signal;
a second FM demodulator that demodulates the intermediate frequency bandpass filter output into a baseband signal;
A space diversity baseband synthesis receiver consisting of an anti-phase hybrid that combines the outputs of 2FM demodulators. L 1 = R + I ... (1) L 2 = R - I ... (2) where R is the first and second received wave frequency I is the intermediate frequency
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56180165A JPS5881347A (en) | 1981-11-10 | 1981-11-10 | Space diversity base band combining receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56180165A JPS5881347A (en) | 1981-11-10 | 1981-11-10 | Space diversity base band combining receiver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5881347A JPS5881347A (en) | 1983-05-16 |
| JPS623622B2 true JPS623622B2 (en) | 1987-01-26 |
Family
ID=16078529
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56180165A Granted JPS5881347A (en) | 1981-11-10 | 1981-11-10 | Space diversity base band combining receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5881347A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4396900T1 (en) * | 1992-12-22 | 1997-07-31 | Motorola Inc | HF antenna switch and method for its operation |
-
1981
- 1981-11-10 JP JP56180165A patent/JPS5881347A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5881347A (en) | 1983-05-16 |
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