JPH0133056B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a receiving device used for mobile communications, etc., and in particular to a base station that performs wireless communication with a mobile transmitting device that transmits radio waves only during communication. This invention relates to a receiving device. The present invention provides a mobile station, a plurality of fixed stations that communicate with the mobile station using the same frequency,
Each of the fixed stations of the mobile radio communication system includes a control station that selects one of the plurality of fixed stations and selectively connects a radio communication line between the selected fixed station and the mobile station. It is used as a receiving device installed in

[Description of prior art]

Conventionally, in mobile communications, where a large number of fixed stations are placed to communicate with mobile stations, a zone configuration is generally used where the same frequency is used repeatedly at a certain distance in order to make effective use of frequencies. It will be done. Normally, this distance is determined so that radio waves from a mobile station do not reach multiple fixed stations at the same time, but due to effects such as fading or the complexity of the terrain, radio waves may be received by multiple fixed stations at the same time. Sometimes something happens.

For example, in Figure 1, there are fixed stations 1 and 2, and mobile station 4 is within the range of fixed station 2, but weak radio waves are also reaching fixed station 1, and the electric field level is as shown in Figure 2 A and B. Assume that it is as shown in .

Conventionally, in this type of fixed station receiving apparatus, as shown in the block diagram of the conventional apparatus shown in FIG. 8 and output as an audio signal.

On the other hand, the presence or absence of a received electric field is determined by the radio wave detection circuit 9 receiving the signal from the intermediate frequency circuit 6, determining the input electric field above the reference point and sending out a radio wave detection signal. The signal is processed by the time constant circuit 1 in order to maintain the connection of the line even in the event of a momentary interruption of the electric field due to fading or other effects during a call.
0 from the sending circuit 11 to the control station 3 as radio wave detection information. Therefore, Figure 2A
Even for a very low input electric field that moves up and down the decision point of the radio wave detection circuit, the radio wave detection information is information on the presence of radio waves over a certain period of time, as shown in Figure 2C. will be sent. Therefore, the radio wave detection information of fixed stations 1 and 2 are both "present", and it is not possible to determine which fixed station the mobile station 4 is within the range of. In this way, mobile station 4
When a call is made from the fixed stations 1 and 2, radio wave detection information is sent to the control station 3 almost simultaneously. Normally, the control station monitors the radio wave detection information from each fixed station sequentially on a time-sharing basis, but if the radio wave detection information is detected earlier at fixed station 1 than at fixed station 2, fixed station 1 first monitors the radio wave detection information from each fixed station. A communication line is configured through the fixed station 1 by confirming the radio wave detection information of the mobile station, and radio wave detection information from the fixed station 2 that is later confirmed regarding the same mobile station is not accepted. In other words, conventional devices sometimes configure a communication line with a mobile station through a fixed station with a lower electric field level even though there is a fixed station with a higher electric field level, which has the disadvantage of deteriorating the quality of communication. Was.

[Purpose of the invention]

The present invention eliminates the above-mentioned drawbacks, and provides a receiving device for a fixed station that allows a communication line to be configured between a mobile station and a mobile station through a fixed station with a higher electric field level, thereby enabling wireless communication with high communication quality. The purpose is to provide.

[Key points of the invention]

The receiving device of the present invention includes a radio wave detection circuit that detects that an incoming radio wave is received at a set level or higher, and operates when a connection signal indicating that the line of the receiving device is connected is received from a source other than the receiving device. a time constant circuit that allows a certain predetermined time from when the radio wave detection circuit operates until it sends out an output; The device is characterized in that the time constant is shortened or eliminated when the connection signal is not received, and the time constant is lengthened when the connection signal is received.

[Explanation based on examples]

Hereinafter, the present invention will be explained with reference to the drawings and an embodiment of the device. FIG. 4 is a block diagram of a fixed station receiving device according to an embodiment of the present invention, FIG. 5 is a circuit diagram, and FIG. 6 is a diagram of a fixed station 1. , 2 shows a time chart of radio wave detection information.

In FIG. 4, the same reference numerals as in FIG. 3 are the same structural blocks as in FIG. The difference is that the output of the radio wave detection circuit 9 is sent to a switching circuit 12, and this switching circuit 12 switches whether the output is sent directly to the sending circuit 11 or via the time constant circuit 10. The switching control of the switching circuit 12 can be performed by the output of the signal receiving circuit 13 which receives the connection signal from the control station 3.

Next, the operation of the receiving apparatus of this embodiment will be explained.

In FIG. 4, the output of the radio wave detection circuit 9 is sent to a switching circuit 12, and a signal receiving circuit 13 receives a connection signal sent from the control station 3 only when a line is connected.
When the output of the signal receiving circuit 13 is "absent", the switching circuit 12 is connected to the time constant circuit 10 side, and when the output of the signal receiving circuit 13 is "absent", the switching circuit 12 is directly connected to the radio wave detection circuit 11. The radio detection information is sent to the control station 3 without a time constant. That is, until the communication line is connected, the radio wave detection information has no time constant, and after the communication line is connected, it is sent out with a sufficient time constant.

In FIG. 5, assuming that the mobile station 4 is within the range of the fixed station 2 as in FIG. 1, the control station 3 monitors the presence or absence of radio detection information of the fixed stations 1 and 2 by
These two stations are repeatedly switched at regular intervals, but when the radio wave detection information output of either fixed station is "present" for a certain period of time, a connection signal is sent to the signal receiving circuit 13 of that fixed station. Then, the connection operation with that fixed station is performed.

Now, the radio wave detection information from fixed station 1 is
The received electric field level from mobile station 4 received by
As shown in Figure A, the detection output of the radio wave detection circuit 9 moves up and down near the radio wave detection judgment point without passing through the time constant circuit 10, so it follows the received electric field as shown in Figure 6C. It will change over time. Therefore, in the control station 3, since the radio wave detection information does not become "present" for a certain period of time, the control station does not send a connection signal to the fixed station 1 and does not perform a connection operation with the fixed station 1. In this way, the control station 3
A line connection is not made to a fixed station whose electric field is so low that it exceeds or exceeds the judgment criteria of the radio wave detection circuit 9.

On the other hand, since the received electric field level of the fixed station 2 is sufficiently higher than the radio wave detection judgment point as shown in FIG.
As shown in FIG. 6D, the radio wave detection information remains "present" for a certain period of time. Therefore, the control station 3 sends a connection signal to the fixed station 2 and performs a connection operation with the fixed station 2. The fixed station 2 switches the switching circuit 12 to the time constant circuit 10 side by receiving this connection signal with the signal receiving circuit 13, and from then on, the detection output of the radio wave detection circuit 9 passes through the time constant circuit 10, and the switch circuit 12 is switched to the time constant circuit 10 side. This prevents line disconnections due to aging, etc.

In the above embodiment, the case where the time constant is "none" has been explained, but the present invention is not limited to this, and any time constant may be used as long as it does not affect the monitoring time of the radio wave detection information of the control station. For example, it may have a short time constant. Furthermore, although the radio wave detection circuit has been described in terms of electric field detection, it may be of any type as long as the detection output changes depending on the input electric field, such as noise detection.

〔Effect of the invention〕

As described above, according to the receiving device of the present invention, a line can be connected to a fixed station with a higher received electric field level, and a very high quality communication line can be constructed.

[Brief explanation of drawings]

FIG. 1 is a line configuration diagram of a conventional device. FIG. 2 is a time chart of radio wave detection information of fixed stations 1 and 2 by a conventional device. FIG. 3 is a block diagram of a conventional fixed station receiver. FIG. 4 is a block diagram of a fixed station receiver according to an embodiment of the present invention. FIG. 5 is a line configuration diagram of an embodiment of the present invention. FIG. 6 is a time chart of radio wave detection information of fixed stations 1 and 2 by the apparatus according to the embodiment of the present invention. 1, 2...Fixed station, 3...Control station, 4...Mobile station, 5...Mixer circuit, 6...Intermediate frequency amplification circuit, 7...Demodulation circuit, 8...Low frequency circuit, 9...
Radio wave detection circuit, 10... Time constant circuit, 11... Information sending circuit, 12... Switching circuit, 13... Signal receiving circuit.

Claims (1)

[Claims] 1. A radio wave detection circuit that detects that an incoming radio wave from a mobile station is received at an electric field level equal to or higher than a predetermined setting level, and a time constant that gives a certain time constant to the detection output of this radio wave detection circuit. and a detection circuit that sends the detection output that has passed through the time constant circuit to a control station as radio wave detection information for selective connection of a communication line. A receiving device comprising: a signal receiving circuit that receives a signal; and a circuit that changes the time constant of the time constant circuit in accordance with the received output of the signal receiving circuit.