JPH0628350B2 - Electric field strength monitor method - Google Patents

Description

The present invention relates to an electric field strength monitoring method, and more particularly to an electric field strength monitoring method in a master station of a time division multidirectional multiplex wireless communication system.

[Conventional technology]

The time division multi-directional multiplex wireless communication system is used as a subscriber wireless system that accommodates a plurality of slave stations scattered around a master station.

A communication input signal input from the outside of the system to each slave station is interface-converted and time-division multiplexed in the indoor unit of the master station to become a downlink main signal suitable for a wireless line. The downlink main signal is converted into a modulated wave by a master station transmitter / receiver installed outdoors such as on a tower, and then sent out. Each slave station sends out a communication signal to the outside of the system as a burst-like modulated wave at the timing assigned to itself. The master station transceiver receives the demodulated wave from each slave station and demodulates it into an upstream main signal. The indoor unit of the master station converts the upstream main signal into an interface and outputs it as a communication output signal to the outside of the system.

The master station monitors the received electric field strength of the modulated wave from each slave station as needed for system maintenance.

That is, the level signal output by the master transceiver (corresponding to the received electric field strength) (generally, the wireless receiver has a function to output the level signal) is sampled at the timing assigned to the modulated wave transmission of each slave station. The received electric field strength is monitored for each slave station.

[Problems to be solved by the invention]

Such a conventional electric field strength monitoring method requires outdoor work because the monitoring work can be performed only near the transmitter / receiver of the master station, and is particularly dangerous when the monitoring work is performed due to a failure in bad weather. It has the drawback of being involved.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks and to provide a field intensity monitor method capable of performing a monitoring operation not only outdoors where the master station transceiver is installed but also indoor installation sites.

[Means for solving problems]

The electric field strength monitoring method of the present invention is an interface unit for converting a communication input signal, which is a digital signal, into a transmission interface so as to be suitable for a wireless transmission path and outputting it as a downlink main signal, and converting an uplink main signal into a reception interface and outputting it as a communication output signal. And converting the downlink main signal into a downlink modulation wave and transmitting the downlink modulation wave to a plurality of slave stations, receiving the uplink modulation wave from the slave station, demodulating and outputting as the uplink main signal, and representing the received electric field strength. In the electric field intensity monitoring method of the master station of the time division multi-directional multiplex wireless communication system in which the transceiver that outputs the level signal is installed separately, an identification signal for arbitrarily designating the slave station to be monitored is generated, and the slave station A portable monitor device for displaying a level by inputting a second level signal representing the received electric field intensity corresponding to a station, and the interface unit. A first multiplexing circuit that is installed in contact with the first main circuit and that multiplexes the identification signal input from the monitor device with the downlink main signal, and is installed close to the transceiver, and outputs the identification signal from the downlink main signal. A first separation circuit for separating, and a switching circuit that is installed in the vicinity of the transceiver and selects and outputs one of the identification signals input from the first separation circuit or the monitor device,
Installed in the vicinity of the transceiver, sampling the first level signal at a timing corresponding to the identification signal input from the switching circuit, and bifurcating the two to obtain two second level signals. A level detection circuit that outputs one to the monitor device, and a second level signal that is installed close to the transceiver and that multiplexes the second level signal, which is the other output of the level detection circuit, into the main signal. It is configured to include a multiplexing circuit and a second separation circuit which is installed in the vicinity of the interface unit and separates the second level signal from the upstream main signal and outputs the second level signal to the monitor device.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment.

FIG. 1 is a block diagram showing an embodiment of the electric field strength monitoring system of the present invention.

In the embodiment shown in FIG. 1, the outdoor unit 1 which outputs the upstream main signal 107 / level signal 105 and inputs the downstream main signal 103 / identification signal 104, and the upstream main signal 107 / identification signal 10
4. Indoor unit 2 that receives communication input signal 109 and outputs downlink main signal 103, level signal 105, and communication output signal 108; monitor device 3 that outputs identification signal 104 and receives level signal 105; and upstream main signal 107 is an outdoor device 1
From the indoor device 2 to the indoor device 2, and the downstream signal line 5 from the indoor device 2 to the outdoor device 1 to transmit the downlink main signal 103.

The outdoor device 1 inputs an antenna 11, a master station transceiver 12 which is connected to the antenna 11 and outputs a level signal 101 / uplink main signal 102 and inputs a downlink main signal 103, an output of a switching circuit 17 and a level signal 101. Level signal 10
5, the level detection circuit 13 that outputs 5 and the level signal 105
A-D conversion circuit 1 for inputting a signal and outputting a level signal 106
4, a multiplexing circuit 15 which inputs the upstream main signal 102 and the level signal 106 and outputs the upstream main signal 107, a separation circuit 16 which inputs the downstream main signal 103 and outputs the downstream main signal 103 and the identification signal 104, Separation circuit 16 or terminal a ₁
And a switching circuit 17 to which the identification signal 104 is input. The level signal 105 is also output to the terminal a ₂ .

The indoor unit 2 inputs the upstream main signal 107 and receives the upstream main signal 1
07. Separation circuit 21 that outputs the level signal 106, a D-A conversion circuit 22 that inputs the level signal 106 and outputs the level signal 105 to the terminal b ₂ , an identification signal 104 from the terminal b _1, and a downlink main signal 110. Enter and enter the down main signal 10
3, and the interface unit 24 that inputs the upstream main signal 107 / communication input signal 109 and outputs the downstream main signal 110 / communication output signal 108.

The monitoring device 3 includes an identification signal generator 31 that outputs the identification signal 104 to the terminal c ₁ and a level signal 10 from the terminal c _2.
And a display unit 32 for inputting 5, and has a portable structure.

FIG. 2 is an explanatory diagram showing frame configurations of the upstream main signals 102 and 107 and the downstream main signals 103 and 110.

As shown in FIG. 2, these main signals include a common signal time slot group S ₀ and communication signal subframes S ₁ to S ₁ to
S _n (n is the total number of slave stations).

First, the communication operation of the embodiment shown in FIG. 1 will be described.

A plurality of communication input signals 109 input to the indoor unit 2 from a switchboard etc.
Signal is converted into a signal and input to the multiplexing circuit 23, and the downlink main signal 1
It becomes 03. The operation of the multiplexing circuit 23 is not related to the communication operation. The downlink main signal 103 is the downlink signal line 5 and the outdoor device 1.
Input to the master station transmitter / receiver 12 via the separation circuit 16 of
It is converted into a modulated wave and transmitted from the antenna 11.

The modulated wave transmitted by each slave station is input to the master station transceiver 12 via the antenna 11 and demodulated to become the upstream main signal 102. The upstream main signal 102 is input to the multiplexing circuit 15 and becomes the upstream main signal 107. The operation of the multiplexing circuit 15 is also not related to the communication operation. The upstream main signal 107 is transmitted through the upstream signal line 4 and the separation circuit 21 of the indoor unit 2 to the interface unit 2
4 into a signal and converted into a plurality of communication output signals 108, which are output to a converter or the like.

Next, the electric field strength monitor operation of the embodiment shown in FIG. 1 will be described.

The identification signal generator 31 of the monitor device 3 generates an identification signal 104 which is arbitrarily set and designates one of the slave stations.

When performing a monitor operation near the outdoor device 1, the terminals c ₁ and c ₂ of the monitor device 3 are connected to the terminals a ₁ and a ₂ of the outdoor device 1. When this connection is made, the switching circuit 17 causes the terminal a ₁
The identification signal 104 input from is selected and output to the level detection circuit 13.

The master station transceiver 12 receives the input level of input from the antenna 11 (this level is proportional to the received electric field strength).
The level signal 101 corresponding to is output. The level detection circuit 13 samples the level signal 101 at the timing of the communication signal subframe corresponding to the slave station designated by the identification signal 104 among the communication signal subframes S _{1 to} S _n of the upstream main signal 102. It is output as 105.

The display unit 32 of the monitor device 3 inputs the level signal 105 via the terminals a ₂ and c ₂ to display the level. As a result, the received electric field strength corresponding to the slave station designated by the identification signal generator 31 is displayed on the display 32.

When performing a monitor operation near the indoor device 2, the terminals c ₁ and c ₂ of the monitor device 3 are connected to the terminals b ₁ and b ₂ of the indoor device 2. The multiplexing circuit 23 inserts the identification signal 104 input via the terminals c ₁ and b ₁ into an empty time slot of the common signal time slot group S ₀ of the downlink main signal 110 and outputs it as the downlink main signal 103.

The separation circuit 16 of the outdoor device 1 separates the identification signal 104 from the downlink main signal 103. The switching circuit 17 is the outdoor device 1
Identification signal 10 to the terminal _c 1 · _{c 2} terminal _a 1 · _{a 2} to the monitor device 3 is not connected separating circuit 16 outputs
4 is selectively output.

On the other hand, the level signal 105 is analog-digital converted by the A / D conversion circuit 14 to become the level signal 106. The multiplexing circuit 15 determines the identification signal 1 in the downlink main signal 110.
The level signal 106 is inserted into the time slot of the upstream main signal 102 corresponding to the time slot used for inserting 04 and output as the upstream main signal 107.

The separation circuit 21 of the indoor unit 2 separates the level signal 106 from the upstream main signal 107. The level signal 106 is digital-analog converted by the D-A conversion circuit 22 to become the level signal 105, and is sent to the monitor device 3 via the terminals b ₂ and c _2.
Is input to the display unit 32 of. As a result, in this case as well, the received electric field strength corresponding to the slave station designated by the identification signal generator 31 is displayed on the display 32.

〔The invention's effect〕

As described in detail above, the electric field strength monitoring method of the present invention transmits the identification signal designating the slave station to be monitored from the indoor unit to the outdoor unit and also represents the received field strength corresponding to the designated slave station. Since the signal can be transmitted from the outdoor device to the indoor device, it is possible to monitor the received electric field strength not only near the outdoor device but also near the indoor device. Therefore, it is possible to monitor safely and comfortably. Yes, because the identification signal and level signal can be multiplexed and transmitted in the empty time slots of the downlink main signal and uplink main signal, it is possible to monitor the received electric field strength near the indoor device without affecting the communication operation. It is effective, and a monitor device that generates an identification signal and displays the received electric field strength can be carried around. There is an effect that it is economical because it is also used in common in the case of the work.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the electric field strength monitoring system of the present invention, and FIG. 2 is an explanatory diagram showing the frame structure of various main signals in FIG. 1 ... outdoor device, 2 ... indoor device, 3 ... monitor device,
4 ... upstream signal line, 5 ... downstream signal line.

Claims (1)

[Claims] 1. An interface unit for converting a communication input signal, which is a digital signal, into a transmission interface suitable for a wireless transmission path and outputting it as a downlink main signal and converting an uplink main signal into a reception interface and outputting it as a communication output signal; Converts the main signal into downlink modulated waves and sends it to multiple slave stations, receives the upstream modulated waves from the slave stations, demodulates and outputs as the upstream main signal, and outputs the first level signal indicating the received electric field strength. In the field intensity monitoring method of the master station of the time division multi-directional multiplex wireless communication system installed separately from the transceiver, generate an identification signal that arbitrarily specifies the slave station to be monitored, and respond to that slave station. A portable monitor device for displaying a level by inputting a second level signal indicating the received electric field strength, and a portable monitor device installed near the interface part. A first multiplexing circuit that multiplexes the identification signal input from the monitor device with the downlink main signal; and a first multiplexing circuit that is installed close to the transceiver and separates the identification signal from the downlink main signal. And a switching circuit that is installed in the vicinity of the transmitter / receiver and selects and outputs one of the identification signal input from the first separation circuit or the monitor device, and a switching circuit in the vicinity of the transceiver. Is installed in the switching circuit, the first level signal is sampled at a timing corresponding to the identification signal input from the switching circuit, and two second level signals are obtained by branching the two signals, one of which is sent to the monitor device. A level detection circuit for outputting and a second level signal, which is installed close to the transceiver and is the other output of the level detection circuit, are multiplexed with the upstream main signal. And a second demultiplexing circuit that is installed close to the interface unit and that demultiplexes the second level signal from the upstream main signal and outputs the demultiplexed level signal to the monitor device. Electric field strength monitor method.