JP2504015B2 - Pilot signal detection circuit - Google Patents
Pilot signal detection circuitInfo
- Publication number
- JP2504015B2 JP2504015B2 JP62005906A JP590687A JP2504015B2 JP 2504015 B2 JP2504015 B2 JP 2504015B2 JP 62005906 A JP62005906 A JP 62005906A JP 590687 A JP590687 A JP 590687A JP 2504015 B2 JP2504015 B2 JP 2504015B2
- Authority
- JP
- Japan
- Prior art keywords
- pilot signal
- signal
- circuit
- detection circuit
- 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 - Lifetime
Links
Landscapes
- Monitoring And Testing Of Transmission In General (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は周波数分割多重されたパイロット信号の検出
に関し、特に帯域通過フィルタを用いずにパイロット信
号を検出するパイロット信号検出回路に関する。Description: TECHNICAL FIELD The present invention relates to detection of frequency-division-multiplexed pilot signals, and more particularly to a pilot signal detection circuit for detecting pilot signals without using a bandpass filter.
従来、FM通信分野では無線区間での回線及び通信装置
の障害監視を目的として、送信側でFM変調をかける以前
のベースバンド信号にパイロット信号（普通単一正弦波
が用いられる）を周波数分割多重し、受信側では狭帯域
な帯域通信フィルタを用いて受信ベースバンド信号より
パイロット信号を検出していた。Conventionally, in the FM communication field, a pilot signal (usually a single sine wave is used) is frequency-division-multiplexed with a baseband signal before FM modulation on the transmitting side for the purpose of monitoring faults of lines and communication devices in the wireless section. However, the receiving side detects the pilot signal from the received baseband signal using a narrow band communication filter.
例えば、第３図に従来回路の一例を示すように、送信
側Ｓにおいて、ハイブリッド11はパイロット信号発振器
12から出力されるパイロット信号を送信ベースバンドに
多重化して送信ベースバンド信号として出力する。For example, as shown in an example of a conventional circuit in FIG. 3, the hybrid 11 is a pilot signal oscillator on the transmitting side S.
The pilot signal output from 12 is multiplexed with the transmission baseband and output as the transmission baseband signal.
また、受信側Ｒでは、受信ベースバンド信号をカプラ
14により分岐し、帯域通過フィルタ13に通して受信ベー
スバンド信号中のパイロット信号のみを抽出し、これを
検波回路15で検波し、パイロット信号のレベルに対応し
た直流電圧に変換し、この電圧とバイアス回路17により
設定された基準電圧とを比較回路16で比較する。On the receiving side R, the received baseband signal is coupled to the coupler.
It is branched by 14, and only the pilot signal in the received baseband signal is extracted through the bandpass filter 13, this is detected by the detection circuit 15 and converted into a DC voltage corresponding to the level of the pilot signal, and this voltage The comparison circuit 16 compares the reference voltage set by the bias circuit 17 with the reference voltage.
ここで、検波回路15の出力電圧が基準電圧より高けれ
ば、比較回路16はパイロット信号を検出したと判断し、
パイロット信号検出信号を出力する。また通信回線又は
通信装置等の障害により信号レベルの低下等が生じた場
合、検波回路15からの出力電圧は低下し、これが基準電
圧より低下した場合、比較回路16はパイロット信号検出
信号を出力しなくなる。Here, if the output voltage of the detection circuit 15 is higher than the reference voltage, the comparison circuit 16 determines that the pilot signal is detected,
The pilot signal detection signal is output. Further, when the signal level is lowered due to a failure of the communication line or the communication device, the output voltage from the detection circuit 15 is lowered, and when it is lower than the reference voltage, the comparison circuit 16 outputs a pilot signal detection signal. Disappear.
上述した従来のパイロット信号検出回路では、ベース
バンド信号よりパイロット信号を抽出する手段として帯
域通過フィルタを用いているが、特にパイロット信号の
み通過させるためには狭帯域でかつ遮断特性が急峻な帯
域通過フィルタが必要となる。しかしこのような帯域通
過フィルタは、通常では回路構成が複雑で大きくなると
ともに調整に時間がかかり、さらにフィルタの帯域の中
心周波数が温度変化により変動するので温度補償回路が
必要となり、帯域通過フィルタが高価で大型なものにな
るという問題がある。In the conventional pilot signal detection circuit described above, a bandpass filter is used as a means for extracting the pilot signal from the baseband signal, but in particular, in order to pass only the pilot signal, a bandpass with a narrow band and steep cutoff characteristics is used. A filter is needed. However, such a bandpass filter usually has a complicated and large circuit configuration and takes time to adjust.Furthermore, since the center frequency of the band of the filter fluctuates due to temperature change, a temperature compensation circuit is required, and the bandpass filter is There is a problem that it becomes expensive and large.
本発明は帯域通過フィルタを必要とすることがなく、
したがって廉価で小型に構成できるパイロット信号検出
回路を提供することを目的としている。The present invention does not require a bandpass filter,
Therefore, it is an object of the present invention to provide a pilot signal detection circuit which is inexpensive and can be made compact.
本発明のパイロット信号検出回路は、送信側にはパイ
ロット信号を分岐して一方を送信ベースバンドに多重化
し他方を受信側に出力する第２のハイブリッドを設ける
一方、受信側には検波回路の前段に送信側から分岐され
たパイロット信号と受信ベースバンド信号との相関をと
る相関器を設け、更に検波回路は相関器の出力値の実部
及び虚部を夫々２乗検波して相関値の振幅の２乗数を出
力し得るように構成している。The pilot signal detection circuit of the present invention is provided with a second hybrid for branching the pilot signal to the transmitting side and multiplexing one to the transmission baseband and outputting the other to the receiving side, while the receiving side is provided with a preceding stage of the detection circuit. In addition, a correlator for correlating the pilot signal branched from the transmitting side with the received baseband signal is provided, and the detection circuit further square-detects the real part and the imaginary part of the output value of the correlator to detect the amplitude of the correlation value. It is configured to be able to output the squared power of.
次に、本発明を図面を参照して説明する。 Next, the present invention will be described with reference to the drawings.
第１図は本発明の一実施例を示し、図においてＳは送
信側、Ｒは受信側を示している。FIG. 1 shows an embodiment of the present invention. In the figure, S indicates a transmitting side and R indicates a receiving side.
送信側Ｓにおいて、１はハイブリッドであり、パイロ
ット信号発振器２から出力されたパイロット信号（普通
は単一正弦波）をハイブリッド８で２分岐し、そのうち
一方を送信ベースバンド信号に多重化する。分岐された
他方のパイロット信号は相関器３に入力される。On the transmission side S, 1 is a hybrid, and a pilot signal (usually a single sine wave) output from the pilot signal oscillator 2 is branched into two by a hybrid 8, and one of them is multiplexed with a transmission baseband signal. The other branched pilot signal is input to the correlator 3.
受信側Ｒにおいて、受信ベースバンド信号はカプラ４
により分岐され、前記相関器３に入力され、ここで送信
側のパイロット信号と相関がとられる。所定の相関がと
られた後、信号は検波回路５で検波されて直流電圧とし
て出力され、これが比較回路６においてバイアス回路７
に設定された基準電圧と比較され、比較結果に基づいて
パイロット信号検出信号が出力されることになる。On the receiving side R, the received baseband signal is the coupler 4
And is input to the correlator 3 where it is correlated with the pilot signal on the transmission side. After the predetermined correlation is obtained, the signal is detected by the detection circuit 5 and output as a direct current voltage, which is then output by the bias circuit 7 in the comparison circuit 6.
It is compared with the reference voltage set to, and the pilot signal detection signal is output based on the comparison result.
ところで、パイロット信号には普通単一正弦波が用い
られるので、これを Pt（ｔ）＝ ｊ（ωpt＋α） （１） とおく。ここで、wpはパイロット信号の角周波数であ
る。 By the way, usually a single sine wave is used for the pilot signal.
Pt (t) = j (ωpt + α) (1) Where wpIs the angular frequency of the pilot signal
You.
また、受信ベースバンド信号は第２図に示すような周
波数配置となっており、図においてＡは周波数分割多重
された多重電話信号、Ｂはパイロット信号である。Further, the received baseband signal has a frequency arrangement as shown in FIG. 2, in which A is a frequency division multiplexed telephone signal and B is a pilot signal.
ここで、受信ベースバンド信号中のパイロット信号Ｂ
を Pr（ｔ）＝ｒ ｊ（ωpt＋β） （１） とおくと、相関器３の出力には送信側のパイロット信号
と受信ベースバンド信号中のパイロット信号との相関成
分 が出力される。上式において、Ｔは相関器の積分回路
（ローパスフィルタ）の時定数である。（１）式と
（２）式を（３）式に代入すると、 となる。 Here, pilot signal B in the received baseband signal
Pr (t) = r j (ωpt + β) (1), the output of the correlator 3 is the pilot signal on the transmission side.
Correlation between the received signal and the pilot signal in the received baseband signal
MinuteIs output. In the above equation, T is the integrating circuit of the correlator
It is the time constant of (low pass filter). Equation (1)
Substituting equation (2) into equation (3),Becomes
さて、送信側のパイロット信号と受信ベースバンド信
号の多重電話信号との相関については、パイロット信号
の周波数と多重電話信号の各周波数との差の周波数で単
振動するビート数は無数に重なったものとなるが、これ
らは相関器の積分回路（ローパスフィルタ）の時定数Ｔ
を大きくすることにより遮断することができる。したが
って、相関器３の出力には（４）式で示された送信側の
パイロット信号Pt（ｔ）と受信ベースバンド信号中のパ
イロット信号Pr（ｔ）との相関値が出力され、受信ベー
スバンド中のパイロット信号を相関値として抽出したこ
とになる。（４）式の相関値の実部と虚部をWR，WIとお
くと、（４）式は、 Ｗ＝r cos（β−α）＋jr sin（β−α） ＝WR＋jW1 …（５） と表現できる。Now, regarding the correlation between the pilot signal on the transmission side and the multiplex telephone signal of the received baseband signal, the number of beats that single-oscillate at the frequency of the difference between the pilot signal frequency and each frequency of the multiplex telephone signal is innumerable. However, these are the time constant T of the integrating circuit (low-pass filter) of the correlator.
It can be cut off by increasing. Therefore, the correlation value between the pilot signal Pt (t) on the transmission side and the pilot signal Pr (t) in the reception baseband signal, which is represented by the equation (4), is output to the output of the correlator 3 and the reception baseband signal is output. This means that the inside pilot signal is extracted as the correlation value. (4) putting the real part and the imaginary part W R, W I of the correlation values of formula (4) is, W = r cos (β- α) + jr sin (β-α) = W R + jW 1 It can be expressed as (5).
このため、検波回路５は相関器３の実部と虚部の各出
力WR及びWIを夫々２乗検波した後、和をとりWR 2＋WI 2と
なる直流電圧を出力する。したがって、検波回路５は
（５）式に示された相関値の振幅の２乗すなわち受信ベ
ースバンド信号中のパイロット信号の振幅の２乗r2を出
力することになる。Therefore, the detection circuit 5 after each output W R and W I of the real and imaginary part of the correlator 3 detects each square, and outputs a DC voltage as a W R 2 + W I 2 sums. Therefore, the detection circuit 5 outputs the square of the amplitude of the correlation value shown in the equation (5), that is, the square of the amplitude of the pilot signal r 2 in the received baseband signal.
これを７のバイアス回路で予め設定された基準電圧と
６の比較回路にて比較し、検波回路５の出力電圧が基準
電圧より高ければパイロット信号が受信ベースバンド信
号中より正しく検波されたと判定し、パイロット信号検
出信号を出力する。また、無線回線または無線装置の異
常等によりベースバンド信号系にレベル低下を生じた場
合等では、パイロット信号Pr（ｔ）の振幅ｒが低下する
ため、検波回路５の出力電圧がバイアス回路７からの基
準電圧より低下し、比較回路６はパイロット信号が検出
されなかったと判定し、パイロット信号検出信号を出力
しない。This is compared with the reference voltage set in advance by the bias circuit of 7 in the comparison circuit of 6, and if the output voltage of the detection circuit 5 is higher than the reference voltage, it is determined that the pilot signal has been detected correctly in the received baseband signal. , Outputs a pilot signal detection signal. Further, in the case where the level of the baseband signal system is lowered due to an abnormality of the wireless line or the wireless device, the amplitude r of the pilot signal Pr (t) is reduced, so that the output voltage of the detection circuit 5 is changed from the bias circuit 7. The reference voltage is lower than the reference voltage and the comparison circuit 6 determines that the pilot signal is not detected, and does not output the pilot signal detection signal.
以上説明したように本発明は、パイロット信号を分岐
して一方を送信ベースバンドに多重化し他方を受信側に
出力する第２のハイブリッドを送信側に設ける一方、検
波回路の前段に送信側から分岐されたパイロット信号と
受信ベースバンド信号との相関をとる相関器を受信側に
設け、更に検波回路を相関器の出力値の実部及び虚部を
夫々２乗検波して相関値の振幅の２乗数を出力し得るよ
うに構成しているので、高価な帯域通過フィルタを用い
ずに、集積化により小型化された低価格な相関器を用い
ることにより、従来の帯域通過フィルタで用いたような
温度補償も不要となり大幅に調整時間を削減でき、パイ
ロット信号検出回路を小型化，低価格化できる効果があ
る。As described above, according to the present invention, the second hybrid that branches the pilot signal and multiplexes one into the transmission baseband and outputs the other to the receiving side is provided on the transmitting side, while branching from the transmitting side to the preceding stage of the detection circuit. A correlator that correlates the generated pilot signal with the received baseband signal is provided on the receiving side, and a detection circuit is further square-law-detected with the real part and the imaginary part of the output value of the correlator to detect the amplitude of the correlation value by 2 Since it is configured to output a multiplier, by using a low-cost correlator that has been downsized by integration without using an expensive bandpass filter, it is possible to use a conventional bandpass filter. Since temperature compensation is not required, the adjustment time can be greatly reduced, and the pilot signal detection circuit can be made smaller and less expensive.
第１図は本発明のパイロット信号検出回路の一実施例の
ブロック図、第２図は受信ベースバンド信号の周波数配
置図、第３図は従来構成のパイロット信号検出回路のブ
ロック図である。 １…ハイブリッド、２…パイロット信号発振器、３…相
関器、４…カプラ、５…検波回路、６…比較回路、７…
バイアス回路、８…ハイブリッド、11…ハイブリッド、
12…パイロット信号発振器、13…帯域通過フィルタ、14
…カプラ、15…検波回路、16…比較回路、17…バイアス
回路、Ｓ…送信側、Ｒ…受信側、Ａ…多重電話信号、Ｂ
…パイロット信号。FIG. 1 is a block diagram of an embodiment of a pilot signal detecting circuit of the present invention, FIG. 2 is a frequency arrangement diagram of a received baseband signal, and FIG. 3 is a block diagram of a pilot signal detecting circuit having a conventional configuration. 1 ... Hybrid, 2 ... Pilot signal oscillator, 3 ... Correlator, 4 ... Coupler, 5 ... Detection circuit, 6 ... Comparison circuit, 7 ...
Bias circuit, 8 ... hybrid, 11 ... hybrid,
12 ... Pilot signal oscillator, 13 ... Bandpass filter, 14
... coupler, 15 ... detection circuit, 16 ... comparison circuit, 17 ... bias circuit, S ... transmission side, R ... reception side, A ... multiple telephone signal, B
… Pilot signal.
Claims (1)
ベースバンド信号に多重化して出力する送信側と、受信
ベースバンド信号をカプラを通した後に検波回路で検波
し、この検波出力を比較回路においてバイアス回路の基
準電圧と比較して前記パイロット信号を検出する受信側
とからなるパイロット信号検出回路において、前記送信
側にはパイロット信号を分岐して一方を送信ベースバン
ドに多重化し他方を受信側に出力する第２のハイブリッ
ドを設け、前記受信側には検波回路の前段に送信側から
分岐されたパイロット信号と受信ベースバンド信号との
相関をとる相関器を設け、かつ前記検波回路は相関器の
出力値の実部及び虚部を夫々２乗検波して相関値の振幅
の２乗数を出力し得るように構成したことを特徴とする
パイロット信号検出回路。1. A transmission side which multiplexes a pilot signal to a transmission baseband signal by hybrid and outputs it, and a reception baseband signal is detected by a detection circuit after passing through a coupler, and this detection output is detected by a bias circuit in a comparison circuit. A pilot signal detecting circuit comprising a receiving side for detecting the pilot signal in comparison with a reference voltage, wherein a pilot signal is branched to the transmitting side, one is multiplexed to a transmission baseband, and the other is output to the receiving side. A hybrid of two is provided, a correlator for correlating the pilot signal branched from the transmission side with the reception baseband signal is provided in the reception side in the preceding stage of the detection circuit, and the detection circuit is provided with the output value of the correlator. A pilot signal detector characterized in that the real part and the imaginary part are square-law-detected to output a square number of the amplitude of the correlation value. Circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62005906A JP2504015B2 (en) | 1987-01-16 | 1987-01-16 | Pilot signal detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62005906A JP2504015B2 (en) | 1987-01-16 | 1987-01-16 | Pilot signal detection circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63175540A JPS63175540A (en) | 1988-07-19 |
| JP2504015B2 true JP2504015B2 (en) | 1996-06-05 |
Family
ID=11623942
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62005906A Expired - Lifetime JP2504015B2 (en) | 1987-01-16 | 1987-01-16 | Pilot signal detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2504015B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4277076B2 (en) * | 2004-03-09 | 2009-06-10 | Ｎｓｃ株式会社 | Pilot signal detection circuit and semiconductor integrated circuit incorporating the circuit |
-
1987
- 1987-01-16 JP JP62005906A patent/JP2504015B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63175540A (en) | 1988-07-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1134909A1 (en) | Single-cable transmission device for signals and power supply of a surveillance system | |
| JPH053458A (en) | Bi-direction optical transmitting method and device | |
| US7212748B2 (en) | Frequency detection circuit, optical receiver and optical transmission system using the same | |
| SE438393B (en) | RECEIVER FOR COMPATIBLE AM STEREO SIGNALS | |
| JP2504015B2 (en) | Pilot signal detection circuit | |
| JPH06311113A (en) | Method and device for receiving monitor signal | |
| EP0643511B1 (en) | Synchronization circuit for subcarrier signal | |
| JPS616942A (en) | Optical multiplex communication system | |
| US3973203A (en) | Carrier isolation system | |
| US5537613A (en) | Device and method for detecting pilot signal for two-carrier sound multiplexing system | |
| US4409436A (en) | Stereo pilot signal eliminating circuit for AM stereophonic receiver | |
| JPS56102143A (en) | Spectrum diffusion communication system | |
| JP4664896B2 (en) | Information distribution system and method, transmitting apparatus and receiving apparatus | |
| SU1309322A2 (en) | Stereo signal transmission system | |
| JPS5856556A (en) | Tone detection system | |
| JP2776290B2 (en) | Digital transmission system | |
| SU1072276A1 (en) | Device for checking multi-channel radio line | |
| SU934575A1 (en) | Device for transmitting and receiving complementary information in communication channel | |
| SU1434561A1 (en) | Device for receiving phase-manipulated signals | |
| JPH07135481A (en) | Reference signal synchronization form spread spectrum communication system | |
| SU790358A1 (en) | Discrete for receiving frequency-modulated signals with large base | |
| JPS631103A (en) | Frequency stability monitor system | |
| JPH0129099B2 (en) | ||
| KR880000960B1 (en) | Multiple system am stereo reiiever and pilot signal detector | |
| JPS6228615B2 (en) |