JPH02200052A - Data transmitter - Google Patents

Abstract

PURPOSE:To surely secure the coincidence of levels of reception signal quality between its own station and an opposite station with no troublesome control by changing the transmission signal level of either one of its own station and another station in the case a difference of the reception signal quality is produced between both stations. CONSTITUTION:A data transmission/reception part 12 receives the signal sent from a data transmitter of an opposite station via line and sends the received signal to a monitor part 6 as well as to a terminal equipment connected to a terminal connecting terminal 24. A mutual reception signal quality information transmission/reception part 14 receives the reception signal quality information from the opposite station and sends it to a control part 4 via a mutual reception signal quality information line 20. The part 4 compares the reception signal quality information on its own station received from the part 6 with that on the opposite station received from the part 14. Then the part 4 sends a transmission level setting signal to a transmission signal level varying part 8 via a transmission level setting signal line 18 in the case a difference is recognized between both signal quality information and also the signal quality of its own station is inferior to that of the opposite station.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data transmission device, and more particularly to a device for improving the received signal quality of a two-wire full-duplex modem or the like using an echo canceller method.

[Conventional technology]

In conventional data transmission equipment such as two-wire full-duplex modems using the eco-canceller method, the received signal quality of the own station is determined by line characteristics, noise, and echoes from the own station's transmitted signal; When the signal quality has deteriorated, the received signal quality is improved by lowering the transmission level of the own station.

[Problem to be solved by the invention]

Therefore, with conventional data transmission equipment, if the received signal quality of the own station is poor due to echoes, etc., by lowering the transmission level of the own station, even if the received signal quality of the own station is improved, the received signal quality of the other station will not be improved. Therefore, there is a drawback that there is a difference in received signal quality between the own station and the other station. In order to make the received signal quality of the local station and the other station almost the same, the local station and the other station had to compare the received signal quality with each other and adjust the transmission level, which was troublesome and difficult. .

The purpose of the present invention is to eliminate such drawbacks, and when there is a difference in received signal quality between one's own station and another station, each time the transmitting signal level of the station with the worse received signal quality is changed. It is an object of the present invention to provide a data transmission device which makes the quality of received signals almost the same.

[Means to solve the problem]

The present invention is a data transmission device in which a local station and a partner station can transmit received signal quality information to each other via a line, the device comprising: a transmitting/receiving section capable of transmitting/receiving the received signal quality information; a monitor section that takes in data from the monitor section and calculates received signal quality information of the own station; a transmission signal level variable section that can vary the transmission signal level of the transmitter/receiver section; Compare received signal quality information of the own station transmitted to the other station via the transmitter/receiver and fetched from the monitor unit with received signal quality information of the other station sent from the other station via the transmitter/receiver. and a control section that controls the transmission signal level variable section to change the transmission signal level so that when there is a difference in received signal quality, this difference disappears.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a functional block diagram showing an embodiment according to the present invention. This data transmission device is composed of a modem section 2 and a control section 4, and reduces the difference in received signal quality when a difference in received signal quality occurs between the data transmission device of the own station and the data transmission device of the other station. This is a device that controls the

The modem section 2 and the control section 4 are connected to the received signal quality information line 1.
6, a transmission level setting signal line 18, and a mutually received signal quality information line 20, which are connected by three lines, and exchange signals such as received signal quality information. The modem section 2 includes a monitor section 6 that monitors the received signal quality, a transmit signal level variable section 8 that varies the level of the transmit signal, and a transmitting/receiving section 1 that transmits or receives data and received signal quality information.
The transmitting/receiving unit 1O further includes a data transmitting/receiving unit 12 that transmits and receives data, and a mutually received signal quality information transmitting/receiving unit 14 that transmits and receives received signal quality information to and from the other station.

The data transmitting/receiving unit 12 receives a signal transmitted via a line from the data transmission device of the other party, and transmits the received signal to the monitor unit 6, and also transmits the received signal to the terminal device connected to the terminal connection terminal 24. It will also be sent to Further, data input from the terminal device is taken into the data transmitting/receiving section 12, subjected to modulation, etc., and transmitted to the data transmitting device of the partner station. The monitor section 6 takes in the received signal sent from the data transmitting/receiving section 12, calculates the received signal quality by determining, for example, the error power of the received signal using an appropriate threshold, and receives the calculated received signal quality information. The signal quality information is sent to the control unit 4 via the signal quality information line 16. The transmission signal level variable section 8 receives the transmission level setting signal line 1 from the control section 4.
8, the transmission level setting signal is taken in, and the transmission signal level of the data transmission/reception section 12 is changed. The mutual reception signal quality information transmitting/receiving section 14 receives reception signal quality information from the partner station, and sends the received signal to the control section 4 via the mutual reception signal quality information line 20. The control unit 4 compares and determines the received signal quality information of its own station sent from the monitor unit 6 and the received signal quality information of the other station sent from the mutual received signal quality information transmitting/receiving unit 14. If a difference is recognized and the received signal quality of the own station is poor, a send level setting signal is sent to the sending signal level variable section 8 via the sending level setting signal line I8. Further, the control section 4 performs comprehensive control of each section.

FIG. 2 is a block diagram showing the configuration when transmitting data using this data transmission device.
2 and a partner station terminal 30 are connected via a local data transmission device 24, a line 26, and a partner data transmission device 28. In the local data transmission device 24, the modem section 2a and the control section 4a have a received signal quality information line 16a and a transmission level setting signal line 18a.

They are connected by three mutual reception signal quality information lines 20a, and signals such as reception quality information are exchanged. Similarly, in the partner station data transmission device 2B, the modem section 2b and the control section 4b are connected to the received signal quality information line 16b1.
They are connected by three lines, a transmission level setting signal line 18b and a mutually received signal quality information line 20b, through which signals are exchanged and control is performed to improve the received signal quality.

Next, the operation of this embodiment will be explained. When bidirectional data transmission is performed between the own terminal 22 and the other terminal 30, the data transmitted from the own data transmission device 24 to the other terminal data transmission device 28 is transferred to the other terminal. The signal is received by the device 28 and taken into the control section 4b via the modem section 2b and the received signal quality information line 16b. The modem section 2b receives the data transmitted from the local data transmission device 24, and transmits the data to the data transmitting/receiving section 1 of the transmitting/receiving section 10.
2. The received signal quality information is sent to the received signal quality information line 16b via the monitor section 6.

The received signal quality information taken into the control unit 4b of the partner station data transmission device 28 is transmitted through the mutual received signal quality information line 20.
b, is transmitted to the data transmission device 24 of the local station via the modem section 2b and line 26, and taken into the control section 4a via the modem section 2a of the data transmission device 24 of the local station and the mutually received signal quality information line 20a. In the modem section 2b of the other station data transmission device 28, the received signal quality information is transmitted to the local station data transmission device 24 via the mutual reception signal quality information transmitting/receiving section 14 of the transmitting/receiving section 10. In the section 2a, the received signal quality information from the other station is sent to the mutually received signal quality information line 20a via the mutually received signal quality information transmitter/receiver 14 of the transmitter/receiver 10.

On the other hand, the data transmitted from the data transmission device 2 of the other party to the data transmission device 24 of the local station is
The received signal quality information is taken into the control section 4a as received signal quality information of the own station via the modem section 2a of No. 4 and the received signal quality information line 16a.

The control unit 4a of the own station data transmission device 24 compares the received signal quality information of the own station and the other station, and if the difference is greater than a predetermined value and the received signal quality is worse than that of the other station,
A transmission level setting signal is sent from the control section 4a to the modem section 2a via the transmission level setting signal line 18a to change the transmission signal level of the local data transmission device 24. In the modem section 2a, the transmission signal level variable section 8 receives the transmission level setting signal from the control section 4a, and the transmission signal level variable section 8 changes the transmission signal level of the data transmission/reception section 12 of the transmission/reception section 10.

At the same time as the control section 4a of the own station data transmission device 24, the control section 4b of the opposite station data transmission device 28 also captures and compares received signal quality information of the own station and the opposite station. If the difference in received signal quality is greater than the specified value, for example, both stations calculate the difference between the standard value of received signal quality and the received signal quality of the 100 stations and the partner station, and the station with the larger difference transmits. Change the signal level. That is, of both stations, the station with the poorer received signal quality changes the transmitted signal level to improve the received signal quality.

When changing the transmission signal level, since both stations have the maximum transmission signal level at the start of communication, the transmission signal level is changed in fixed steps in the direction of decreasing the level. When the transmission signal level is changed and the quality of both received signals becomes approximately the same level, the transmission of the transmission level setting signal from the control section to the modem section is stopped, and the change in the transmission signal level is stopped. However, if there is no improvement in the received signal quality at all even if the station with the worse received signal quality changes the transmitted signal level, return the transmitted signal level to the level before changing it, and then The stations constantly monitor the difference in received signal quality, and when the difference exceeds a specified value, the station with the worse received signal quality changes the transmitted signal level to improve the received signal quality and improve the quality of both stations. Control is performed to keep the received signal quality at approximately the same level.

〔Effect of the invention〕

As explained above, the present invention attempts to improve received signal quality while monitoring the difference in received signal quality between the local station and the partner station. Is this a hassle? This has the effect of making it possible to reliably equalize the received signal quality levels of the own station and the other station without performing A adjustment.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration when transmitting data using this embodiment. 2...Modem unit 4...Control unit 6...Monitor unit 8...Transmission signal level variable unit 10...Transmission/reception unit 22...Self Station terminal 24...Own station data transmission device 2G...Line 28...Counter station data transmission device 30...Counter station terminal

Claims (1)

[Claims] (1) A data transmission device that allows a local station and a partner station to transmit received signal quality information to each other via a line, the device comprising: a transmitting/receiving section capable of transmitting/receiving the received signal quality information; a monitor section that takes in data and calculates received signal quality information of the own station; a transmission signal level variable section that can vary the transmission signal level of the transmitting/receiving section; and a transmitting/receiving section that takes in the received signal quality information of the own station from the monitor section; Compare received signal quality information of the own station transmitted to the other station via the unit and fetched from the monitor unit with received signal quality information of the other station sent from the other station via the transmitting/receiving unit; A data transmission device comprising: a control unit that controls the transmission signal level variable unit to change the transmission signal level so that when there is a difference in received signal quality, the difference disappears.