JPH11205182A - Transmitter/receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the number of transmitters/receivers to be simultaneously used per unit area by controlling transmission power at the time of transmission while judging the receiving state of a received signal based on the contents of the received signal provided by a reception circuit and a reception level provided by a reception level detecting means. SOLUTION: The frame of a transmission signal from the transmitter/receiver of a communicating party is acquired through an antenna 1, SW 2 and a reception circuit 3. Besides, the reception level of the received signal acquired by the reception circuit 3 is acquired while using a reception level detecting means 4, the transmission power at the time of next transmission is set to a transmission power control circuit 7 corresponding to the received result and reception level of the received signal acquired by a control means 6, and transmission power control information to accompany that power is set. When the received signal provided by the reception circuit 3 is normal and the reception level provided by the reception level detecting means 4 is higher than a preset reference value, transmission power is set to 5 mW. Thus, the number of transmitters/receivers to be simultaneously used per unit time can be remarkably increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a transceiver such as a telecontroller for communicating with a specified low power radio.

[0002]

2. Description of the Related Art Conventionally, the configuration of a transceiver for communicating with a specified low power radio is generally known as shown in FIG.
That is, the conventional transceiver is an antenna 11 for both transmission and reception.
A switch 12 for switching between transmission and reception, a reception circuit 13 for obtaining a reception signal via the antenna 11, and a reception circuit 1
3. A reception level detection means 14 for detecting the reception level of the reception signal obtained in step 3, a transmission circuit 15 for transmitting the transmission signal via the antenna 11, and a control means 1 for controlling the whole.
Before starting the transmission, a free channel is detected by carrier sense, a communication channel is determined, and transmission is started. The transmission power at the time of transmission is generally 10 mW which is the upper limit of the transmission power of the specified low power radio
Was kept constant.

[0003]

However, in the transmitter / receiver having the conventional configuration, the transmission power at the time of transmission is constant at the upper limit of the transmission power of 10 mW. The area occupying the communication channel has become larger than necessary. Therefore, in order for another transceiver to communicate on the same channel, it must be far away from the area occupied by the transceiver that was communicating earlier, and the number of simultaneous transceivers used per unit area is very small and limited. It was.

Therefore, there is a problem that when trying to use many transceivers simultaneously in a small area, many transceivers that cannot transmit are generated.

As a method for coping with this, it is conceivable to set the transmission power at the time of transmission to a value reduced in advance, but in this case, the communicable distance is shortened and the transmission power at the time of transmission is reduced. As compared with the case where the power is constant at 10 mW, the possibility that another transceiver performs communication on the same channel at a shorter distance becomes higher, so that the probability of being affected by the transmission radio wave of the other transceiver becomes higher and stable. There is a problem that it is difficult to obtain a communication state.

[0006] The present invention solves such a conventional problem, can increase the number of simultaneously used transceivers per unit area, and achieve a stable communication state even in a situation where the communication state is deteriorating. It is an object of the present invention to provide a transceiver capable of returning quickly.

[0007]

SUMMARY OF THE INVENTION In order to solve this problem, a transceiver according to the present invention includes a receiving circuit for obtaining a received signal via an antenna, and a receiving level of the received signal obtained by the receiving circuit. Receiving level detection means, and a transmission circuit for transmitting a transmission signal via the antenna,
The transmission level control circuit controls the transmission power at the time of transmission based on the reception level of the reception level detection means, and the transmission power control circuit determines the transmission power based on the control signal output from the control means.

According to the configuration of the present invention, it is possible to increase the number of simultaneously used transceivers per unit area, and to quickly return to a stable communication state even when the communication state is deteriorating. A transceiver that can be obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a receiving circuit for obtaining a reception signal via an antenna, and a reception level detection for detecting a reception level of the reception signal obtained by the reception circuit. Means, a transmission circuit for transmitting a transmission signal via the antenna, and control means for controlling the transmission power at the time of transmission based on the reception level of the reception level detection means, the control means is a reception circuit By determining the reception state of the reception signal based on the content of the obtained reception signal and the reception level obtained by the reception level detecting means and controlling the transmission power at the time of transmission, the optimum transmission according to the communication state is achieved. It has the effect that power control can be performed.

According to a second aspect of the present invention, in the first aspect of the present invention, the transmission power control information at the time of transmission is transmitted to the other party together with the transmission signal so that the transmission power control information is transmitted to the other party. The transmission power control of the transmitting side is synchronized with the transmission power control of the transmitting side, and the transmission power control of both the transmitting and receiving transceivers is matched to more reliably perform the optimum transmission power control according to the communication state. It has the effect of being able to.

According to a third aspect of the present invention, in the first aspect of the present invention, the reception signal obtained by the reception circuit is normally received, and the reception level obtained by the reception level detection means is set in advance. If the reference value is higher than the set reference value, the transmission power at the time of transmission is reduced, and the number of transceivers used simultaneously per unit area can be increased.

According to a fourth aspect of the present invention, in the first aspect of the invention, the reception signal obtained by the reception circuit is abnormal reception and the reception level obtained by the reception level detection means is set in advance. If it is higher than the reference value, the transmission power at the time of transmission is increased, and even in a situation where the communication state is deteriorating due to the influence of the transmission radio waves of other transceivers communicating on the same channel. This has the effect that it is possible to quickly return to a stable communication state.

According to a fifth aspect of the present invention, in the first aspect of the invention, the reception signal obtained by the reception circuit is normal reception, and the reception level obtained by the reception level detection means is set in advance. If it is lower than the reference value, the transmission power at the time of transmission is to be increased, and even in a situation where the communication state is deteriorating such as the distance between the transceivers during communication is increasing, a stable communication state is quickly established. It has the effect of being able to return.

According to a sixth aspect of the present invention, in the first aspect of the invention, the reception signal obtained by the reception circuit is abnormal reception and the reception level obtained by the reception level detection means is set in advance. If it is lower than the reference value, the transmission power at the time of transmission is increased, and even in a situation where the communication state is deteriorating, such as a shield between the transmitting and receiving transceivers, a stable communication state is quickly established. Has the effect of being able to return to

According to a seventh aspect of the present invention, in accordance with the fourth aspect of the present invention, the reception signal obtained by the receiving circuit is normally received even if a predetermined time or more has passed. If the reception level obtained by the reception level detection means cannot be higher than the preset reference value, the communication is switched to another communication channel and communication is resumed, and the deterioration of the communication state continues. In such a situation, it is possible to quickly return to a stable communication state.

An embodiment of the present invention will be described below with reference to FIGS. (Embodiment 1) FIG. 1 is a block diagram showing a configuration of a transceiver according to a first embodiment of the present invention, FIG. 2 is a transmission signal format in the embodiment, and FIG. 3 is a flowchart in the embodiment. is there. In FIG. 1, 1
Is an antenna for both transmission and reception, and 2 is an S for switching between transmission and reception.
W, 3 is a receiving circuit for obtaining a received signal via the antenna 1, 4 is a receiving level detecting means for detecting the receiving level of the received signal obtained by the receiving circuit 3, 5 is a transmitting signal via the antenna 1 A transmission circuit 6 for controlling transmission power at the time of transmission based on the reception level of the reception level detection means 4, and a transmission power control 7 for determining transmission power based on a control signal output from the control means 6. Circuit.

The operation of the present embodiment will be described below with reference to FIGS. 1, 2 and 3. Here, in order to simplify the explanation, the following description will be made assuming that the transmission power increase state during transmission is 10 mW output and the transmission power decrease state is 5 mW output.

First, a communication channel is set for the receiving circuit 3 and carrier sensing is performed. As a result,
If it is determined that there is a carrier, the communication channel is changed and carrier sense is performed again. When it is determined that there is no carrier, the communication is started by recognizing that the channel is an empty channel. Here, the transmission power at the start of transmission is set to 5 mW for the transmission power control circuit 7, and the transmission signal is also set. Is set to 5 mW. In this state, by making a communication connection with the transceiver of the communication partner, a normal communication state is established, and the transmission operation and the reception operation of one frame are performed alternately.

In the transmission operation, a transmission signal is transmitted from the control means 6 to the transmission circuit 5. The transmission signal has a format as shown in FIG. 2, and transmits transmission power control information at the time of transmission to the transmission partner together with input / output control information and the like. The transmission signal is transmitted by the transmission circuit 5, the transmission power control circuit 7, the SW
2. Transmission is performed at the transmission power set in the transmission power control circuit 7 via the antenna 1. The transmitted transmission signal is obtained via the antenna 1, SW2, and the receiving circuit 3 of the transceiver of the communication partner, and the transceiver of the communication partner reduces the transmission power at the next transmission according to the transmission power control information of the received signal. It is set in the transmission power control circuit 7, and the associated transmission power control information is set.

In the receiving operation, one frame of a transmission signal from the transceiver of the communication partner is obtained via the antenna 1, SW2, and the receiving circuit 3, and the received signal obtained by the receiving circuit 3 using the reception level detecting means 4 is obtained. The reception level is obtained, and the transmission power for the next transmission is set in the transmission power control circuit 7 according to the reception result and the reception level of the reception signal previously obtained by the control means 6, and the transmission power control information associated therewith is set. I do.

Here, when the reception signal obtained by the reception circuit 3 is normal reception and the reception level obtained by the reception level detection means 4 is higher than a preset reference value, communication is stable. In this state, the transmission power during transmission is set to 5 mW.

Next, when the reception signal obtained by the reception circuit 3 is abnormal reception and the reception level obtained by the reception level detection means 4 is higher than a preset reference value,
Since it can be expected that the communication state is degraded due to the influence of the transmission radio waves of other transceivers communicating on the same channel, the transmission power at the time of transmission is set to 10 mW.

If the reception signal obtained by the reception circuit 3 is normal reception and the reception level obtained by the reception level detection means 4 is lower than a preset reference value, the communication between the transmitting and receiving transceivers is performed. Since it can be expected that the communication state is degraded due to an increase in the distance, the transmission power at the time of transmission is set to 10 mW.

If the reception signal obtained by the reception circuit 3 is abnormal reception and the reception level obtained by the reception level detecting means 4 is lower than a preset reference value,
Since it is expected that the communication state is degraded due to a shield between the transmitting and receiving transceivers, the transmission power at the time of transmission is set to 10 mW.

Even if the above operation is continued for a certain period of time, the reception signal obtained by the reception circuit 3 is normally received, and the reception level obtained by the reception level detection means 4 is set in advance. If a state higher than the reference value cannot be obtained, it is determined that communication cannot be continued on the current communication channel, and communication is resumed by changing to another communication channel and continuing the operation after carrier sense. .

As described above, in the present embodiment, the reception state of the reception signal is determined based on the content of the reception signal obtained by the reception circuit 3 and the reception level obtained by the reception level detection means 4, and the communication becomes stable. In this state, by controlling the transmission power at the time of transmission to 5 mW, the number of simultaneously used transceivers per unit area can be increased twice as much as the conventional one, and the communication state becomes unstable. In the state, by controlling the transmission power at the time of transmission to 10 mW, it is possible to quickly return to a stable communication state. Also, by transmitting transmission power control information at the time of transmission to a transmission partner together with a transmission signal, transmission power control at the time of transmission at the transmission partner is synchronized with transmission power control at the transmission side, and transmission of both the transmitting and receiving transceivers is performed. By matching the power control, it is possible to obtain an effect that optimal transmission power control according to the communication state can be performed more reliably.

In this embodiment, the transmission power at the time of transmission is controlled in two ways, 5 mW and 10 mW.
It is also possible to increase or decrease the transmission power in smaller steps within the range of the transmission power specified for the specific low-power radio.

Further, in this embodiment, the transmission power of both the transmitting and receiving transceivers is controlled based on one of the receiving states between the transmitting and receiving transceivers. It is also possible to perform more optimal transmission power control by checking the reception state of the transceiver.

It is also possible to perform more stable transmission power control by providing a plurality of preset reception level reference values and providing hysteresis when the transmission power increases and decreases.

[0030]

As described above, according to the present invention, it is possible to increase the number of simultaneously used transceivers per unit area and to quickly return to a stable communication state even in a situation where the communication state is deteriorating. In addition, it is possible to obtain the effect that the transmission power control of both the transmitting and receiving transceivers can be matched, and the optimum transmission power control according to the communication state can be performed more reliably.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a transceiver according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a transmission signal format according to the first embodiment.

FIG. 3 is a flowchart according to the first embodiment;

FIG. 4 is a block diagram showing a configuration of a conventional transceiver.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 antenna 2 SW 3 reception circuit 4 reception level detection means 5 transmission circuit 6 control means 7 transmission power control circuit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroaki Ono 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (7)

[Claims] 1. A transceiver for communicating with a specified low power radio, comprising: a reception circuit for obtaining a reception signal via an antenna; and a reception level detection means for detecting a reception level of the reception signal obtained by the reception circuit. And a transmission circuit for transmitting a transmission signal via the antenna, and control means for controlling transmission power at the time of transmission based on the reception level of the reception level detection means, wherein the control means is obtained by a reception circuit. A transmission / reception device for controlling the transmission power at the time of transmission by judging the reception state of the reception signal based on the content of the reception signal and the reception level obtained by the reception level detection means. 2. The transmission power control at the time of transmission at the transmission partner side is synchronized with the transmission power control of the transmission side by transmitting transmission power control information at the time of transmission to the transmission partner together with the transmission signal. The transceiver according to claim 1, wherein 3. When the reception signal obtained by the reception circuit is normal reception and the reception level obtained by the reception level detection means is higher than a preset reference value, the transmission power at the time of transmission is reduced. The transceiver according to claim 1, wherein: 4. When the reception signal obtained by the reception circuit is abnormally received and the reception level obtained by the reception level detection means is higher than a preset reference value, the transmission power at the time of transmission is increased. The transceiver according to claim 1, wherein: 5. When the reception signal obtained by the reception circuit is normal reception and the reception level obtained by the reception level detection means is lower than a predetermined reference value, the transmission power at the time of transmission is increased. The transceiver according to claim 1, wherein: 6. If the reception signal obtained by the reception circuit is abnormal reception and the reception level obtained by the reception level detection means is lower than a preset reference value, the transmission power at the time of transmission is increased. The transceiver according to claim 1, wherein: 7. The transceiver according to claim 4, wherein the reception signal obtained by the reception circuit is normally received and the reception level is obtained by the reception level detection means even after a predetermined time has elapsed. A transceiver characterized by shifting to another communication channel and restarting communication when a state where the reception level is higher than a preset reference value cannot be obtained.