JPH02309721A - Automatically transmission and reception level adjusting transmitter-receiver - Google Patents

Abstract

PURPOSE:To eliminate the need for an AGC circuit on an opposite transmitter receiver side and to simplify the transmitter and receiver by providing a means which holds a reception output level constant and varies the level of a sent signal reversely to variation in reception input level. CONSTITUTION:A signal 9 inputted to a transmitter receiver 2 is supplied to a transmission part 3 for level conversion, frequency conversion, etc., and sent to the automatically transmission and reception level adjusting receiver 1 as an inter-device signal 13. In the automatically transmission and reception level adjusting transmitter receiver 1, level conversion, frequency conversion, etc., are performed by a reception part 5 and a reception level adjustment part 6 corrects level variation generated on a transmission line. The adjusting signal of a reception level adjustment part 6, on the other hand, is sent out to a transmission level control part 7 as well. The transmission level control part 7 commands a transmission level adjustment by exactly the same value as the reception level adjustment. Therefore, a constant-level reception output signal is obtained without providing any AGC circuit at the reception part of an opposite transmitter receiver.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention corrects level fluctuations caused by the transmission path when transmitting and receiving signals between a WA device and a gB device, and improves the performance of each device. The present invention relates to a transmitting/receiving device that maintains a constant level of the final output signal (output signal inside each station, not on the transmission line side).

(Prior art) Conventionally, AG has been used as a method for automatically correcting level fluctuations.
C (＾automatic Ga1n Control:
There is a method called automatic gain control), which is used for wireless devices,
It is used in hammered telephones, etc. In other words, when transmitting and receiving signals between equipment fA and equipment WB, conventionally each device has a received signal level v8 adjustment section, and the final output signal of each device (not the output on the transmission line side, but the output inside each station) signal) to a constant level.

(Problem to be Solved by the Invention) However, in the conventional AGC method described above, each device detects the received signal level and automatically adjusts the level fluctuation to keep the final stage output constant. Not only when transmitting and receiving signals between two devices, but also when transmitting and receiving signals between one device and many other devices, there is a drawback that each device must have an AGC circuit.

In view of the above-mentioned problems of the prior art, an object of the present invention is to provide means for keeping the receiving output level constant and fluctuating the level of the transmitting signal in the opposite direction to the fluctuation of the receiving input level, thereby making it possible to transmit and receive data from the other party. An object of the present invention is to provide a transmitting/receiving device that eliminates the need for an AGC circuit in the device.

(Means for Solving the Problems) The present invention has the following means configuration to achieve the above object.

That is, the transmitting/receiving device of the present invention includes: receiving means for receiving an input signal from a receiving transmission line; and receiving output level adjustment for adjusting the level so that a substantially constant level of receiving output is obtained even if there is a level fluctuation in the input signal. Transmission means for sending a transmission signal to a transmission transmission path; Transmission level control means for receiving an adjustment signal from the reception output level adjustment means and varying the level of the transmission signal in a direction opposite to the level fluctuation of the input signal. This is a transmitting/receiving device with automatic transmitting/receiving level adjustment, characterized by comprising: and;

(Example) Hereinafter, an example of the apparatus of the present invention will be described with reference to the drawings.

FIG. 1 shows a block diagram illustrating the configuration of an apparatus according to an embodiment of the present invention and a block diagram illustrating the configuration of a transmitting/receiving device that is the other party for transmission and reception.

1 in the figure is an embodiment of the transmission/reception level automatic adjustment transmitting/receiving device of the present invention. The transmitting/receiving level automatic adjustment transmitting/receiving device 1 includes a transmitting section 8
, a reception section 5, a reception level adjustment section 6, and a transmission level control section 7. The transmitting/receiving device 2 includes a transmitting section 3 and a receiving section 4.
It consists only of In the transmitter/receiver 2, the input signal 9 undergoes level conversion, frequency conversion, etc. in the transmitter 3, and is sent as an inter-device signal 13 to the transmitter/receiver 1 with automatic transmission/reception level adjustment. The inter-device signal 13 is affected by the surrounding environment on the transmission path, causing level fluctuations, S/N fluctuations, etc., and reaches the transmission/reception level automatic adjustment transmitting/receiving device 1. In the device 1, the receiving section 5 performs level conversion, frequency conversion, etc., and the reception level adjusting section 6 corrects level fluctuations occurring on the transmission path, so that the final output signal 10 is always at a constant level. It is maintained. On the other hand, the adjustment signal from the reception level control section 6 is also sent to the transmission level control section 7. The transmission level control section 7 instructs the transmission level adjustment section to have exactly the same value as the reception level adjustment section.

Specifically, when the level of the input signal to all receiving sections 5 decreases by, for example, 2 dB due to a change in the state of the receiving transmission path, the receiving level adjusting section 6 adjusts the level by 2 dB in order to keep the level of the final output signal 10 constant. For example, the amplification gain is adjusted to increase by 2 dB to compensate for the decrease in dB.

By the way, since the receiving transmission path and the sending transmission path are usually the same system and the same route, they are affected by the surrounding environment in the same way.
If the signal propagating through the receiving transmission path is attenuated by 2 dB, this means that the signal propagating through the transmitting transmission path will also be attenuated by 2 dB.

Therefore, in order to keep the level of the received output signal of the receiving section 4 of the transmitting/receiving device 2 constant, the transmitting signal level of the transmitting section 8 must be set to 2.
It would be better to increase it by dB.

Conversely, when the receiving input level increases by 2 dB, the amplification gain is decreased by 2 dB, so the transmitting output level also increases by 2 dB.
It will be controlled to lower it. That is, the transmission level control section 7 controls the transmission output level of the transmission section 8 to increase or decrease by the same amount as the reception level adjustment section.

The above explanation is for the case where the receiving and transmitting transmission paths are affected by the surrounding environment in the same way, but the degree of influence is different because, for example, the receiving and transmitting channels use different carrier frequencies. For example, if the receiving transmission path is 3
In the case of a 1.5 dB change in the transmission transmission path, the reception level adjustment section
．． The setting is such that transmission level control is performed with changes as small as 5 dB.

The transmission level control section 7 performs such control.

The transmitting unit 8 performs level conversion, frequency conversion, etc. on the signal to be transmitted, and then performs the transmission level correction instructed by the transmission level control unit 7 as described above, and sends the signal to the transmitting and receiving device as an inter-device signal 14. Send to ff12. The equipment W
2 receives the inter-device signal 14, performs level conversion, frequency conversion, etc. in the receiving section 4, and outputs it as a received output signal 11 (final output signal). Since this output is at a level obtained by correcting the transmission signal itself of the transmitter 8 as described above, it will be at a constant level even if the receiver 4 does not have a special automatic correction function.

Application examples of the transmission/reception level automatic adjustment transmission/reception device of the present invention in a band around 4 KHz include telephones and supervisory control devices, and examples of application of the transmission/reception level automatic adjustment transmitting/receiving device of the present invention in a band of around 4 kHz include wireless equipment.

(Effects of the Invention) As explained above, the transmitting/receiving level automatic adjustment transmitting/receiving device of the present invention not only includes a receiving level adjusting section for correcting level fluctuations in a transmission path, but also transmits a transmitting output level in conjunction with the receiving level adjusting section. Since the transmission is controlled to compensate for level fluctuations in the communication channel, there is an advantage that a received output signal can be obtained at a constant level without providing an AGC circuit in the receiving section of the transmitting/receiving device of the other party, and the device configuration can be simplified.

In particular, in a system in which a large number of counterpart transmitting/receiving devices are installed to perform transmission/reception, the advantage that the device configuration can be simplified becomes remarkable.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a device according to an embodiment of the present invention and a block diagram of the configuration of the other party's transmitting/receiving device. 1... Transmission/reception level automatic adjustment transmitting/receiving device, 2.
...Transmitting/receiving device, 3... Transmitting section, 4
．． 5... Receiving section, 6... Reception level adjustment section, 7... Transmission level control section, 8...
...Transmission unit, 9... Signal, 10.11.
...Reception output signal (final output signal), 12...
...signal, 13.14...signal between devices.

Claims (1)

[Claims] Receiving means for receiving an input signal from a receiving transmission line; Receiving output level adjusting means for adjusting the level so that a substantially constant level of receiving output is obtained even if there is a level fluctuation in the input signal; a transmitting signal to the transmitting transmission line; and a transmission level control means that receives an adjustment signal from the reception output level adjustment means and changes the level of the transmission signal in a direction opposite to the level fluctuation of the input signal. A transmitting/receiving device that automatically adjusts the transmitting/receiving level.