JP2541104B2 - Automatic matching control device - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention is used in communication lines. INDUSTRIAL APPLICABILITY The present invention is used for an automatic matching control device for a hybrid circuit for two-wire / four-wire conversion connection. In particular, it relates to an automatic matching control device for equipment used outdoors.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram of a conventional automatic matching control device.

Conventionally, the automatic matching control device has a structure as shown in FIG. In FIG. 2, the mixer 8 adds the control tone signal 107 out of the voice band from the control tone generation circuit 7 to the transmission signal 102. The band-pass filter 5 extracts only the wrap-around control tone signal 106 added on the transmitting side from the sneaking signal 105 sneaking on the receiving side due to the matching state with the matching impedance Zl on the two-wire side, and compares the phase levels. Output to the circuit 12. The phase control circuit 13 performs the phase correction of its own device in advance to compare and judge the control tone signal 107 from the control tone generation circuit 7 with the sneak control tone signal 106 sneak to the receiving side, and then the reference control tone signal is outputted. 114 is output to the phase level comparison circuit 12. The phase level comparison circuit 12 compares the phase and level of the loop control tone signal 106 and the reference control tone signal 114, and if the loop control tone signal 106 is the control tone signal 107 of its own device, its determination result. DC signal 1 which is
08 is output to the control circuit 3. The control circuit 3 outputs a matching control signal 109 according to the DC signal 108, and the matching circuit 2 increases or decreases the matching impedance Zn according to the matching control signal 109 and wraps around to the receiving side of the four-wire circuit. The signal 106 is controlled to be minimum, interference of the control tone signal with the opposite device is eliminated, and the hybrid circuit for the two-wire four conversion connection is automatically matched.

When the automatic matching is not performed, it is preferable that the impedance Zl on the two-wire side is constant, but if the impedance Zl changes, the matching circuit 2 cannot perform matching, and the transmission signal 102 on the four-wire side is not obtained. The level of the sneak signal 103 that wraps around to the receiving side increases, causing reverberation or ringing. Usually, this phenomenon occurs, and particularly in the outdoor equipment, the impedance Zl on the two-wire side greatly changes depending on the line length for connection and the operating environment condition, and this effect is great.

There is also a proposal to compare the transmission level and the recirculation signal level and increase or decrease the matching impedance to minimize the recirculation signal level (JP-A-1-209822).

[0006]

However, in the automatic matching control device of the conventional example, in order to avoid the interference with the opposing two-wire / four-wire conversion circuit, it is dealt with by correcting the wrap-around phase in the device in advance. However, there is a possibility that the phase may be the same as that of the own device due to the connection distance with the automatic matching device that is oppositely connected, and there is a unavoidable drawback.

The present invention solves the above-mentioned drawbacks, and provides an automatic matching control device capable of reducing the interference of control tone signals of the automatic matching devices connected to each other and performing the best matching control. The purpose is to

[0008]

The present invention relates to a hybrid circuit for performing two-wire / four-wire conversion , a control tone signal which is a signal outside the voice band mixed with a transmission signal from the four-wire side , and a control tone signal for the receiving side. Matching means for increasing or decreasing the matching impedance of the hybrid circuit based on the level comparison result with the input loop control tone signal is provided .
Control tone generator circuit that generates a control signal
Mixer that mixes the transmission signal with the transmission signal, and
Extracts the wraparound control tone signal from the wraparound signal
Band pass filter and matching control signal corresponding to the DC signal
Based on the control circuit that outputs the
Matching to increase or decrease the matching impedance of hybrid circuits
In the automatic matching control device including a circuit , the matching means includes means for stopping and holding the adjustment of the matching impedance when the recirculation control tone signal becomes minimum, and the means for stopping and holding is a two-wire system. Side connection status
And outputs a loop detection signal when the opposite device is connected
Loop detection circuit that detects the transmission signal from the four wire side
A voice detection circuit that outputs a voice detection signal when
Matching open based on the loop detection signal and the voice detection signal.
An automatic matching start control circuit that outputs a start control signal, and
The control tone signal and the wrap-around based on the start control signal.
The comparison of the level with the control tone signal is started and the comparison result
Output the DC signal according to the
Level at which the judgment signal is output when it is judged that it has become small
A comparison / determination circuit, wherein the automatic matching start control circuit is
A procedure for releasing the matching start control signal based on the judgment signal
It is characterized by including a step .

[0009]

[Function] When the connection state does not change, paying attention to the fact that the matching condition does not change so much, the loop detection circuit monitors the change in the connection state, and controls only the first call when the state has changed. It is possible to reduce the interference of the control tone signal of the automatic matching device connected by the following and perform the best matching control.

[0010]

Embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, the automatic matching control apparatus comprises a hybrid circuit 1 for performing a two-wire / four-wire conversion, a control tone signal 107 mixed with a transmission signal 102 from the four-wire side, and a sneak loop wrapping around to the receiving side. Matching means for increasing or decreasing the matching impedance of the hybrid circuit 1 based on the level comparison result with the control tone signal 106 is provided.

A feature of the present invention is that the matching means includes means for stopping and holding the adjustment of the matching impedance when the bypass control tone signal 106 becomes minimum. .

That is, the means for stopping and holding the loop detection circuit 11 for monitoring the connection state on the two-wire side and outputting the loop detection signal 112 when the opposite device is connected,
A voice detection circuit 9 that outputs a voice detection signal 111 when the transmission signal 102 from the four-wire side is detected, and an automatic matching start control that outputs a matching start control signal 110 based on the loop detection signal 112 and the voice detection signal 111. Circuit 10,
Control tone signal 107 based on matching start control signal 110
And the turn-around control tone signal 106 are compared with each other, a DC signal 108 corresponding to the comparison result is output, and a decision signal 113 is output when the turn-around control tone signal 106 is determined to be minimum. Including the determination circuit 6,
The automatic matching start control circuit 10 includes means for releasing the matching start control signal 110 based on the determination signal 113.

The control tone signal 107 is a signal outside the voice band.

Further, the matching means includes a control tone generating circuit 7 for generating a control tone signal 107, a mixer 8 for mixing the control tone signal 107 and the transmission signal 102,
A band-pass filter 5 for extracting a bypass control tone signal 106 from the bypass signal 105 that has spilled to the receiving side, and a DC signal 1
Control circuit 3 which outputs a matching control signal 109 according to 08
And the matching circuit 2 that increases or decreases the matching impedance of the hybrid circuit 1 based on the matching control signal 109.

The operation of the automatic matching control device having such a configuration will be described.

FIG. 2 is a flow chart showing the operation of the automatic matching control circuit of the automatic matching control device of the present invention. FIG. 3 is a flow chart showing the operation of the automatic matching control circuit of the automatic matching control device of the present invention. 1 to 3, first, when the loop detection circuit 11 detects that the opposing automatic matching control device is connected, it outputs a loop detection signal 112 to the automatic matching start control circuit 10. In the automatic matching start control circuit 10, the transmission signal 102 on the four-wire side is the voice detection circuit 9
Is detected by the loop detection signal 112 and the voice detection signal 111, a predetermined time matching start control signal 1
10 is output to the control tone generation circuit 7 and the level comparison / determination circuit 6. Upon receiving the matching start control signal 110, the control tone generation circuit 7 outputs the control tone signal 107 outside the voice band.
Occurs. The mixer 8 adds the control tone signal 107 to the transmission signal 102 and outputs it to the hybrid circuit 1. The control tone generation circuit 7 also outputs a control tone signal 107 to the level comparison / determination circuit 6 for comparison. The transmission signal 104 to which the control tone signal 107 is added spills to the receiving side according to the matching state of the hybrid circuit 1. The bandpass filter 5 extracts the loop control tone signal 106 from the loop signal 105 and outputs it to the level comparison / determination circuit 6.

The level comparison / determination circuit 6 makes a level comparison / determination between the control tone signal 107 and the extracted loop control tone signal 106, and the DC signal 10 corresponding to the level difference.
8 is output to the control circuit 3. The control circuit 3 uses the DC signal 1
The matching control signal 109 is generated according to the level of 08 and is output to the matching circuit 2. The matching circuit 2 uses the matching control signal 10
The control impedance Zn is increased or decreased according to 9. The control impedance Zn is controlled by this series of operations, and the level comparison / judgment circuit 6 releases the matching start control signal 110 by the judgment signal 113 in the minimum state of the sneak control tone signal 106 and holds the current matching state. It is automatically matched with the impedance Zl on the two-wire side.

[0019]

As described above, the present invention has an excellent effect that the interference of the control tone signals of the automatic matching devices connected to each other can be reduced and the best matching control can be performed.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an automatic matching control device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the automatic matching control circuit of the automatic matching control device of the present invention.

FIG. 3 is a flow chart showing the operation of the level comparison / determination circuit of the automatic matching control device of the present invention.

FIG. 4 is a block configuration diagram of a conventional automatic matching control device.

[Explanation of symbols]

 1 Hybrid Circuit 2 Matching Circuit 3 Control Circuit 4 High Pass Filter 5 Band Pass Filter 6 Level Comparison Judgment Circuit 7 Control Tone Generation Circuit 8 Mixer 9 Voice Detection Circuit 10 Automatic Matching Start Control Circuit 11 Loop Detection Circuit 12 Phase Level Comparator circuit 13 Phase control circuit 102, 104 Transmitting signal 103, 105 Loop signal 106 Loop control tone signal 107 Control tone signal 108 DC signal 109 Matching control signal 110 Matching start control signal 111 Voice detection signal 112 Loop detection signal 113 Judgment Signal 114 Reference control tone signal

Claims (1)

(57) [Claims] 1. A hybrid circuit for performing two-wire / four-wire conversion, and a signal outside the voice band mixed with a transmission signal from the four-wire side.
Comprising alignment means for increasing or decreasing the matching impedance of the hybrid circuit based on a level comparison result of the control tone signal and Kaikomi control tone signal wrapping around to the receiving side is, the matching means generates said control tone signal Control
And a control tone signal and the transmission signal.
From the mixer that mixes with
A bandpass filter for extracting the bypass control tone signal;
A control circuit that outputs a matching control signal according to a DC signal,
Matching of the hybrid circuit based on this matching control signal
In an automatic matching control device including a matching circuit that increases or decreases impedance, the matching means includes means for stopping and holding the adjustment of the matching impedance when the turn-around control tone signal becomes minimum, and this holding and holding is performed. Means to monitor the connection status of the two wire side
Outputs a loop detection signal when an opposite device is connected
When the loop detection circuit and the transmission signal from the four wire side are detected
A voice detection circuit that outputs a voice detection signal when
Matching start control based on the voice detection signal and the voice detection signal.
Automatic matching start control circuit that outputs a control signal
The control tone signal and the wraparound control based on the start control signal
Start comparing the level with the tone signal and respond to the comparison result.
Output the same direct current signal to minimize the shunt control tone signal.
Level comparison that outputs a judgment signal when it is judged that
And a determination circuit, wherein the automatic matching start control circuit is based on the determination signal.
An automatic matching control device comprising means for releasing a matching start control signal .