JPH0150146B2 - - Google Patents
Info
- Publication number
- JPH0150146B2 JPH0150146B2 JP56165801A JP16580181A JPH0150146B2 JP H0150146 B2 JPH0150146 B2 JP H0150146B2 JP 56165801 A JP56165801 A JP 56165801A JP 16580181 A JP16580181 A JP 16580181A JP H0150146 B2 JPH0150146 B2 JP H0150146B2
- Authority
- JP
- Japan
- Prior art keywords
- circuits
- circuit
- detection
- signal
- switching circuit
- 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
- 238000001514 detection method Methods 0.000 claims description 13
- 239000000284 extract Substances 0.000 claims description 3
- 230000007257 malfunction Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
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
- H04B7/0802—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 antenna selection
- H04B7/0817—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 antenna selection with multiple receivers and antenna path selection
- H04B7/082—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 antenna selection with multiple receivers and antenna path selection selecting best antenna path
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】
本発明はスペースダイバシテイ方式に関し、詳
しくは例えばカーラジオにおけるFMマルチバス
ノイズの低減回路に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a space diversity system, and more particularly to a circuit for reducing FM multi-bass noise in a car radio, for example.
従来のFMマルチバスノイズの低減法として
は、第１図に示すように、中間周波回路３よりキ
ヤリア信号を取り出し、該キヤリアレベルによつ
て、FMマルチレツクス５のステレオセパレーシ
ヨンと、高域の周波数特性を下げ、マルチバスノ
イズを聴感的に緩和するものがある。 As shown in Fig. 1, the conventional method for reducing FM multi-bass noise involves extracting a carrier signal from the intermediate frequency circuit 3, and depending on the carrier level, the stereo separation of the FM multi-bass 5 and the high frequency There are some that reduce the characteristics and audibly alleviate multi-bass noise.
しかし、この方法では、マルチバスノイズが完
全には、キヤリアレベルの変化に対応していない
ため、マルチバスノイズを完全になくすことはで
きないという欠点があつた。 However, this method has the disadvantage that multi-bass noise cannot be completely eliminated because it does not completely correspond to changes in the carrier level.
本発明の目的は上記した従来技術の欠点をなく
し、マルチバスノイズを低減するためのスペース
ダイバシテイ方式の制御方式を提供することにあ
る。 SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a space diversity control method for reducing multi-bus noise.
マルチバスノイズの発生時には、キヤリアレベ
ルの変化の他に、中間周波信号に、AM変調成分
が発生する。従つてこのAM成分を検出し、スペ
ースダイバシテイ方式の制御信号として、２系統
の受信回路を切換えれば、マルチバスノイズ除去
に効果がある。 When multi-bass noise occurs, in addition to changes in the carrier level, AM modulation components are generated in the intermediate frequency signal. Therefore, if this AM component is detected and used as a control signal for the space diversity method to switch between the two receiving circuits, multi-bass noise can be effectively removed.
以下、本発明の実施例を第２図により説明す
る。この回路は、２つの受信回路Ａ，A′から成
り、該受信回路の検波回路４，４′の検波出力信
号は夫々信号切換回路１２に供給され、該回路に
て一方の検波出力信号が選択されて後段の出力回
路に導かれる。また中間周波回路３，３′の中間
周波信号はAM検波回路８，８により、AM検波
されてその出力にはAM変調成分のみが取り出さ
れる。このAM変調成分はバンドバスフイルタ
９，９′に供給され、該フイルタにて19KHz〜
60KHzの成分を取り出される。この出力信号は整
流回路１０，１０′にて整流され、次段の比較回
路１１にてそのレベルを比較され、比較回路１１
はこの時AM変調成分の小さい側の受信回路の信
号を出力回路に導く如く上記信号切換回路を制御
する信号を出力する。 Embodiments of the present invention will be described below with reference to FIG. This circuit consists of two receiving circuits A and A', and the detection output signals of the detection circuits 4 and 4' of the receiving circuits are respectively supplied to a signal switching circuit 12, and one of the detection output signals is selected by the circuit. and then guided to the subsequent output circuit. Further, the intermediate frequency signals of the intermediate frequency circuits 3, 3' are subjected to AM detection by the AM detection circuits 8, 8, and only the AM modulation component is extracted as the output thereof. This AM modulation component is supplied to bandpass filters 9 and 9', and the filter
The 60KHz component is extracted. This output signal is rectified by rectifier circuits 10 and 10', and its level is compared by a comparison circuit 11 at the next stage.
At this time, outputs a signal for controlling the signal switching circuit so as to guide the signal of the receiving circuit having the smaller AM modulation component to the output circuit.
要するに本発明はマルチバスノイズ発生時に発
生する成分を取り出し、この成分を利用して信号
切換回路の切換えを制御してなるものである。こ
こで中間周波信号のAM変調成分には、マルチバ
スによつて生じる成分以外の雑音も入つているこ
とから誤動作が発生する。しかしマルチバスノイ
ズがステレオ放送時に特に顕著であることを考え
て、このAM成分のうち、ステレオパイロツト信
号である19KHzからステレオ信号成分の60KHzま
でのAM成分を取り出し、これを制御信号として
いる上記実施例によれば、誤動作は解消できる。 In short, the present invention extracts a component generated when multi-bass noise occurs and uses this component to control switching of a signal switching circuit. Here, malfunctions occur because the AM modulation component of the intermediate frequency signal contains noise other than components generated by the multi-bus. However, considering that multi-bass noise is particularly noticeable during stereo broadcasting, the above implementation extracts the AM component from 19KHz, which is the stereo pilot signal, to 60KHz, which is the stereo signal component, and uses this as the control signal. According to the example, the malfunction can be eliminated.
以上述べた本発明によれば、従来、キヤリアレ
ベルを制御信号としていたため、マルチバスノイ
ズの発生時にキヤリアレベルが変化しない場合に
誤動作していたが、本発明は、マルチバスノイズ
発生時に発生するAM変調成分を制御信号とし
て、２つの受信回路を切換え、歪のない電波を受
信することができるので、スペースダイバシテイ
方式として、誤動作なく、マルチバスノイズを低
減できるという効果がある。 According to the present invention described above, since the carrier level was conventionally used as a control signal, malfunctions occurred when the carrier level did not change when multi-bus noise occurred, but the present invention can prevent malfunctions when the carrier level does not change when multi-bus noise occurs. Since the two receiving circuits can be switched using the AM modulation component as a control signal to receive distortion-free radio waves, this space diversity method has the effect of reducing multi-bass noise without malfunction.
第１図は従来のセパレーシヨン制御回路の、ブ
ロツク図、第２図は本発明の一実施例を示すスペ
ースダイバシテイ方式のブロツク図である。
１……アンテナ、２……FMフロントエンド、
３……IF回路、４……検波回路、５……FMマル
チ回路、６……オーデイオ回路、７……スピーカ
ー、８……AM検波回路、９……バンドバスフイ
ルタ、１０……倍電圧整流回路、１１……比較回
路、１２……切換回路、１′……サブアンテナ、
２′……サブフロントエンド、３′……サブIF回
路、４′……サブ検波回路、８′……サブAM検波
回路、９′……サブ19KHzバンドバスフイルタ、
１０′……サブ倍電圧整流回路。
FIG. 1 is a block diagram of a conventional separation control circuit, and FIG. 2 is a block diagram of a space diversity system showing one embodiment of the present invention. 1...Antenna, 2...FM front end,
3...IF circuit, 4...Detection circuit, 5...FM multi circuit, 6...Audio circuit, 7...Speaker, 8...AM detection circuit, 9...Band bass filter, 10...Voltage double rectifier circuit, 11...comparison circuit, 12...switching circuit, 1'...sub antenna,
2'...Sub front end, 3'...Sub IF circuit, 4'...Sub detection circuit, 8'...Sub AM detection circuit, 9'...Sub 19KHz band bus filter,
10'...Sub voltage doubler rectifier circuit.
Claims (1)
信回路の出力を切換選択して出力回路に導く信号
切換回路と、上記第１、第２の受信回路の中間周
波信号をAM検波する第１、第２の検波回路と、
該第１、第２の検波回路の検波出力から19KHz〜
60KHzまでのAM成分を抽出する第１、第２のバ
ンドバスフイルタと、該フイルタをバスしたAM
成分を整流する第１、第２の整流回路と、該第
１、第２の整流回路に結合され、該整流信号のレ
ベルを比較し、上記信号切換回路を上記第１、第
２の受信回路の上記AM成分の小さい側に切換え
る制御信号を出力する比較器とからなることを特
徴とするスペースダイバシテイ受信方式。1 first and second receiving circuits, a signal switching circuit that switches and selects the outputs of the first and second receiving circuits and guides them to the output circuit, and intermediate frequency signals of the first and second receiving circuits. First and second detection circuits for AM detection;
19KHz ~ from the detection output of the first and second detection circuits
First and second bandpass filters that extract AM components up to 60KHz, and AM bus filters
first and second rectifier circuits that rectify the components; and a signal switching circuit that is coupled to the first and second rectifier circuits, compares the levels of the rectified signals, and connects the signal switching circuit to the first and second receiver circuits. and a comparator that outputs a control signal for switching to the smaller side of the AM component.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56165801A JPS5868328A (en) | 1981-10-19 | 1981-10-19 | Space diversity reception method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56165801A JPS5868328A (en) | 1981-10-19 | 1981-10-19 | Space diversity reception method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5868328A JPS5868328A (en) | 1983-04-23 |
| JPH0150146B2 true JPH0150146B2 (en) | 1989-10-27 |
Family
ID=15819245
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56165801A Granted JPS5868328A (en) | 1981-10-19 | 1981-10-19 | Space diversity reception method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5868328A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4823398A (en) * | 1985-12-23 | 1989-04-18 | Kazuya Hashimoto | Diversity receiver |
| US4882589A (en) * | 1986-12-29 | 1989-11-21 | Hughes Aircraft Company | Coherent switching system for a multiple beam antenna |
| JPS63252024A (en) * | 1987-04-08 | 1988-10-19 | Pioneer Electronic Corp | Space diversity receiver |
-
1981
- 1981-10-19 JP JP56165801A patent/JPS5868328A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5868328A (en) | 1983-04-23 |
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