JPH0492518A - Transmitter/receiver - Google Patents

Abstract

PURPOSE:To attain the control of the reception/transmission electric power in response to the receiving situation of a transmitting destination by changing the transmission output of a radio signal at a transmission means in accordance with a received control signal. CONSTITUTION:A reception level detecting means 14 detects the level of a received signal and outputs a control signal to a control signal transmission means 18 in response to the detected level The means 18 of a transmitter/ receiver A transmits the control signal to a transmitter/receiver B by radio. At the transmitter/receiver A, the control signal is received from the transmitter/receiver B by a control signal reception means 16 and then sent to a transmission output changing means 20. The means 20 changes the transmission output of its own transmitter/receiver in response to the control signal received from the transmitter/receiver B. Thus the undesired power is never consumed at transmission and therefore a transmitter/receiver driven by a battery can perform the communication for a longer period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transceiver including a transmitting circuit and a receiving circuit.

Previously, transmitters and receivers that communicate wirelessly, such as cordless telephones and mobile communication devices, emitted radio waves with the same output whether communicating over short distances or long distances. . That is, in any case, at the time of transmission, a predetermined amount of power is outputted depending on the purpose of communication.

The above specified transmission power is determined by considering the maximum range for each purpose of communication, but if the two transmitters/receivers communicating are much closer to each other than the maximum range. , the power required for communication is much lower than the specified transmission power. Conventionally, even in such cases, transmission was always performed at the specified power (maximum power), resulting in wasted power.

SUMMARY OF THE INVENTION An object of the present invention is to solve such problems and provide a transceiver that can control transmission power according to the reception status of a destination.

In order to achieve the above object, in the present invention, as shown in FIG. Reception level detection means 14 for detecting the level of the received radio signal, control signal transmission means 18 for transmitting a control signal according to the level, control signal reception means 16 for receiving the control signal, and control signal reception means 16 for receiving the control signal. The present invention is characterized by comprising a transmission power changing means 20 that changes the transmission power of the wireless signal in the transmitting means 22 accordingly.

In addition, as shown in FIG. 2(b), the control signal transmitting means 19
The control signal may be superimposed on the radio signal transmitted by the transmitting means 22, and the control signal receiving means 17 may extract the control signal from the radio signal received by the receiving means 12.

Knee pressure - Let A and B be the transmitters and receivers that are communicating wirelessly with each other,
This will be explained with reference to FIG. The radio signal from the transceiver B is received by the receiving means 12 of the transceiver A. This radio signal carries a signal (for example, a voice signal in the case of a radio telephone) that is the main purpose of this communication. The reception level detection means 14 detects the level of this reception signal and sends a control signal according to the magnitude of the level to the control signal transmission means 18.
Output to. The control signal transmitting means 18 of the transceiver A transmits this control signal to the transceiver B by radio. At this time, 1! As shown in Figure J1 (a), the control signal may be transmitted and received using a signal different from the wireless signal that is the main purpose of communication, and the medium may be the same or a different medium may be used. ), the wireless signal may be transmitted and received by being superimposed on the wireless signal as shown in (b) of the same figure. In the case of (b), the control signal receiving means 17 separates and extracts the control signal superimposed on the radio signal, and the control signal transmitting means 19 superimposes the control signal on the original communication radio signal. It becomes something to incorporate.

The same thing is done at the transceiver B, and a control signal corresponding to the level of the signal received by the transceiver B is sent to the transceiver A. In the transceiver A, the control signal from the transceiver B is received by the control signal receiving means 16 (in the case of the mode (b), it is extracted from the received signal), and the transmission output changing means 20
send to The transmission output changing means 20 changes the transmission output of its own transceiver (transceiver A) in response to a control signal from the transceiver B.

Specifically, when the reception level of transceiver B is high, the transmission output of transceiver A is made relatively small, and when the reception level of transceiver B is low, the transmission output of transceiver A is made relatively small. The transmitting means 22 is controlled to increase the size. As a result, the strength of the radio signal output from transceiver A will be reduced to a level necessary and sufficient for reception by transceiver B.

Note that the present invention is applicable to any communication medium that uses wireless communication, and is applicable to transmitters and receivers that use infrared rays, ultrasonic waves, etc. in addition to radio waves.

EXAMPLE 1 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a block diagram showing the configuration of a wireless transceiver to which the present invention is applied. Another one with the same configuration as this transceiver
The operation of this transceiver will be explained below, assuming that it is communicating with the transceiver of the present invention.

First, to explain the normal transmission/reception operation, the high frequency circuit 32 of the receiving section selects a radio wave having the frequency of the other party's transceiver from the radio waves received by the receiving antenna 30, and converts it into an intermediate frequency. The detection circuit 34 extracts an audio signal including a control signal from this intermediate frequency signal, and the receiving audio circuit 36 extracts only the audio signal, amplifies it, and outputs it from the speaker 38. On the other hand, when transmitting, microphone 5
The audio input to 8 is converted into a predetermined audio signal by a transmission audio circuit 56, and modulated to a predetermined transmission frequency by a high frequency circuit 54.

The high frequency signal of the transmission frequency is output by the output signal level control circuit 52.
The output level is adjusted as described later, and the transmitting antenna 50
is emitted as radio waves.

Next, parts related to the present invention will be explained with reference to the flowchart of FIG. When starting communication with this transceiver, transmission begins with the maximum power specified by the standards of the transceiver (step #10). This is because the location of the other party's transceiver is not known at first. When communication is started in this way and a radio wave is received from the other party, the input signal level detection circuit 44 detects the level of the received radio wave. (detects) and sends it to the microcomputer 42 as reception level data (step #12
).

The microcomputer 42 creates control data to be sent to the other party's transceiver based on this reception level data (
Step #14). The control data at this time is shown in Figure 4 (
As shown in a), the transmission output level of the other party may be determined in a unique relationship with the reception level, or as shown in FIG. In this case, the other party may be prompted to increase the energy of the transmitted radio wave by a predetermined small value ΔEO, and if it is 61 or more, to decrease it by ΔEO. Also, the same figure (C)
As shown in Figure 2, data may be used that more precisely indicates the amount of increase/decrease. The microcomputer 42 sends the control data determined in this way to the transmission signal shaping circuit 46, and the shaping circuit 46 sends the control signal generated from this control data to the transmitting side high frequency circuit 54, where it is added to the high frequency signal together with the transmitted audio signal (step # 16). Therefore, the radio waves emitted from the transceiver of this embodiment include control signals in addition to voice signals.

The above processing is performed in the same way in the other party's transceiver, and a control signal corresponding to the reception level is sent from the other party's transceiver to the present transceiver.

In this transceiver, a control signal selection circuit 40 sorts and separates the control signal from the other party included in the received radio waves from the output of the detection circuit 34, restores it to control data, and sends it to the microcomputer 4.
2 (step #18). The microcomputer 42 controls the output signal level control circuit 52 based on control data from the other party.
The level of the transmission output of this transceiver is adjusted by (step #20). As shown above and in Figure 4, when the reception level at the other party's transceiver is low, the transmission level of this transceiver is raised, and when the reception level at the other party is high, the output level of this transceiver is lowered. It will be done. As control signals are exchanged with each other in this way, the transmission output levels of both transmitters and receivers settle down to a level necessary and sufficient for mutual communication. Therefore, no unnecessary transmission power is consumed, and the radio waves do not reach unnecessary locations, reducing the risk of eavesdropping.

In the above embodiment, an example of a transceiver for the purpose of voice communication was taken up, but the present invention is equally applicable to a transceiver for the purpose of data communication. Further, in the above embodiment, the control signal is transmitted superimposed on the normal communication radio waves, but the control signals may be exchanged at a frequency completely different from that of the communication radio waves.

Light m As explained above, according to the present invention, since no more power than necessary is consumed during transmission, a battery-powered transceiver can communicate for a longer period of time. Furthermore, the battery can be made smaller, contributing to the reduction in size and weight of transmitters and receivers such as cordless telephones and mobile communication devices.

Furthermore, since radio waves are emitted only enough to reach the minimum necessary distance, the risk of eavesdropping is reduced, and the number of lines used per unit area of the mobile communication system can be increased.

Further, the medium for transmitting and receiving is not limited to radio waves, but the present invention can be applied in exactly the same manner to cases where wireless communication is performed using infrared rays, ultrasonic waves, etc., and the same effects can be obtained. For example, in the case of a remote control device or the like that sends and receives signals using infrared rays, by applying the present invention, it is possible to prevent the risk that equipment other than the intended device will malfunction.

[Brief explanation of drawings]

Figures 1 (a) and (b) are block diagrams for explaining the basic configuration of the present invention, Figure 2 is a block diagram showing the configuration of a transceiver according to an embodiment, and Figure 3 is a block diagram for explaining the basic configuration of the present invention. FIG. 4(a) is a flowchart of the processing performed. (b) and (C) are graphs showing the relationship between the reception level and the control signal.

Claims (7)

[Claims] (1) In a transmitter/receiver equipped with a transmitting means for transmitting a wireless signal and a receiving means for receiving a wireless signal, the transmitter/receiver includes a reception level detecting means for detecting the level of the wireless signal received by the receiving means, and a control signal corresponding to the level. A transceiver comprising: a control signal transmitting means; a control signal receiving means for receiving the control signal; and a transmitting output changing means for changing the transmitting output of a wireless signal in the transmitting means according to the received control signal. . (2) The transceiver according to claim 1, wherein the control signal transmitting means superimposes the control signal on the radio signal transmitted by the transmitting means, and the control signal receiving means extracts the control signal from the radio signal received by the receiving means. (3) The transceiver according to claim 1 or 2, wherein the control signal defines the transmission output of the other party's transceiver according to the reception level. (4) The control signal controls the transmission output of the other party's transmitter/receiver to be increased by a predetermined increment value when the reception level is lower than a predetermined reference value, and to be decreased by the increment value when it is higher than the reference value. 3. The transmitter/receiver according to claim 1, wherein the transmitter/receiver is configured to: (5) The transceiver according to any one of claims 1 to 4, wherein the propagation medium of the wireless signal is a radio wave. (6) Claims 1 to 4, wherein the propagation medium of the wireless signal is infrared rays.
Transmitter/receiver described in any of the above. (7) Claims 1 to 4, wherein the propagation medium of the wireless signal is an ultrasonic wave.
Transmitter/receiver described in any of the above.