JP3190863B2 - Line switching method for wireless devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates has an outdoor unit disposed outdoors and the indoor unit arranged in the room, inside
Sending and receiving signals between duplexed systems
In addition, the present invention relates to a line switching method for a wireless device capable of mutually switching between active and standby .

[0002]

2. Description of the Related Art A conventional line switching system for a radio apparatus of this type will be described with reference to a block diagram of a conventional line switching system for a radio apparatus shown in FIG.

In a general wireless device, in order to increase the efficiency of maintenance work, an antenna (not shown) serving as an interface with another wireless device as a communication partner and a transmission / reception head are placed outdoors so that work can be performed indoors as much as possible. A configuration in which many circuits such as a modulation / demodulation unit and a digital signal processing unit are arranged in an indoor unit (also called an IDU) and both units are connected by a coaxial cable is often used. ing. The wireless device in FIG. 3 basically has this configuration.

In this wireless device, the indoor unit 10
1A is a duplex system of the first indoor system 201A and the second indoor system 202A, and the outdoor unit 10A
2A also adopts a duplex system of the first outdoor system 301A and the second outdoor system 302A. The duplex indoor unit 101A and the outdoor unit 102A are connected to the first indoor system 201A and the first outdoor system so that each of the high-frequency signals transmitted between the two units can be transmitted and received between the working and standby units. The second indoor system 202A is connected to the second indoor system 202A by a coaxial cable 401.
The coaxial cable 402 is also connected to the outdoor system 302A. The first and second indoor systems 201A and 202A have the same circuit configuration, and the first and second outdoor systems 301A and 302A also have the same circuit configuration.
The circuit for generating the line switching signal _Ssw for switching between the active and standby modes in response to the occurrence of a failure in the wireless device is basically provided in a common part of the indoor unit and the outdoor system except for the indoor system and the outdoor system.

[0005] First, the first indoor system 201A will be described in the case of a current operation. In this system 201A, the main transmitter 1 generates a first main signal, which is usually a data signal, at a carrier frequency f1. The main receiver 2 receives a second main signal having the same signal format as the first main signal at the carrier frequency f2. These main signals are often subjected to 4-phase PSK modulation, but the modulation method is not limited.

[0006] Control signal transmitter (CTX) 3A outdoor unit 102A, produces the control signal S _tc of the first outdoor system 301A at the carrier frequency f3 mainly. The control signal transmitter 3A also controls the line switching signal S _sw for switching the current outdoor system 301A to the outdoor system 302A by the control signal _Stc.
Is superimposed. This signal superposition (multiplexing)
This is performed using a serial converter (P / S) 31. The modulation method of the superimposed signal is arbitrary. Control signal S _tc is ODU1
A lot of data for 02A control is transmitted in a serial data format. Therefore, the line switching signal S _sw is _equal to the number of control signals S _sw
It will be inserted by flagging specific bit positions between _tc bits. Generally, the polling cycle for sending the line switching signal S _sw is on the order of several milliseconds,
If the transfer speed of the communication data is low, it may take several tens of milliseconds to transfer the entire line switching signal _Ssw . For this reason,
The line switching time between the outdoor systems 301A and 302A generally requires several tens of milliseconds.

[0007] Further, in this wireless device, it is convenient to make a telephone call between the indoor unit 101A and the outdoor unit 102A at the time of maintenance. For this reason, an audio signal line is provided. A transmission audio signal S _vt from a predetermined device such as a telephone is input to a modulator 42, and the modulator 42 AM-modulates a carrier S _cw of a carrier frequency f4 from a carrier oscillator 8 with the transmission audio signal S _vt . Note that an amplifier is usually used as a buffer between the predetermined device and the modulator 42. Further, the power transmission unit (TPS) 5 is a power source of the first outdoor system 301A and the outdoor unit 10A.
The power of the common portion of 2A is supplied by DC power.

The first main signal, the second main signal, the superimposed signal of the control signal and the line switching signal, the audio signal, and the DC from the TPS 5 are frequency-multiplexed signals.
The signal is demultiplexed and demultiplexed by the demultiplexer 6a and connected to the first outdoor system 301A through the coaxial cable 401. The carrier frequencies f1, f2, f3, and f4 are frequencies different from each other, for example, about 800 MHz. The multiplexer / demultiplexer 6a
The main transmitter 1, the main receiver 2, the control signal transmitter 3A, and the modulator 42 have band-pass filters 6 of frequencies f1, f2, f3, and f4, respectively.
1, 62, 63 and 64 are connected, and the power transmission unit 5 is connected to a low-pass filter 65 that passes a direct current without passing the frequencies f1, f2, f3 and f4.

The first indoor unit 101A supplies a line switching signal S _sw to the P / S 31 of the second indoor system 202A via the inverter 17. Therefore, if the line switching signal S _sw is a signal for setting the first outdoor system 301A as a standby, the second outdoor system 302A is switched to the current operation. Conversely, if the line switching signal S _sw is a signal that activates the first outdoor system 301A, the second outdoor system 302A becomes a standby.

[0010] Next, a description will be given of a case of working the first outdoor system 301A, the system 301A converts the first main signal from the main transmitter 1 for example to the transmission high frequency signal S _t of 18GHz band antenna To another wireless device. In addition, the receiving head 10 receives a received high frequency signal _Sr having the same signal format and close frequency as the first main signal from the same wireless device from the antenna. A power amplifier may be connected to the transmission head 9 after frequency conversion, and a low-noise amplifier may be connected to the reception head 10 after the antenna. When there is only one antenna, transmission and reception are separated by an antenna duplexer. If the antennas are separate, it is not necessary to separate the transmission and reception by the antenna duplexer.

The control signal receiver (CRX) 11A serially converts the control signal S _rc and the superimposed signal of the line switching signal S _sw into a serial signal.
The signals are separated by a parallel converter (S / P) 32. Control signal S _rc of the separated serial form (which is a control signal signals obtained by reproducing the S _tc) is used for control of ODU102A. On the other hand, the separated line switching signal _Stsw is sent to the outdoor system switch 18 belonging to the common part of the ODU 102. Then, the outdoor system switch 18, which is a set of logic circuits,
The second outdoor system 302A is switched to the working side, and the first outdoor system 301A is switched to the standby side using a predetermined circuit.

The AM-modulated audio signal (S _vt ) is supplied to a demodulator 12A. The demodulator 12A uses the AM
The modulated voice signal (S _vt ) is subjected to AM demodulation, and the demodulated received voice signal _Svr is output to a predetermined device such as a telephone via the capacitor 13. Note that an amplifier is usually used as a buffer between the capacitor 13 and the predetermined device. Further, the power receiving unit (RPS) 15 is a power source of the first outdoor system 301A and the outdoor unit 102A.
DC power is supplied as a power source for the common part of. The multiplexer / demultiplexer 6b has the same configuration as the multiplexer / demultiplexer 6a, and inputs / outputs various signals input / output to / from the first outdoor system 301A to corresponding circuits.

The second indoor system 202A and the second outdoor system 302A have the same functions and functions as the first indoor system 201A and the first outdoor system 301A, respectively.
Although it has an effect, it is a standby when the first system is in operation, and is active when the first system is in standby.

[0014]

In the above-described prior art wireless device switching method, the line switching signal generated from the indoor system is inserted between the control signals, so that the polling cycle is as long as several tens of milliseconds. In addition, there has been a problem that line switching on the order of several μS, which is ideal in switching between the working and the standby of the outdoor system, cannot be performed.

Further, a parallel-serial converter and a serial-parallel converter are required for multiplexing and demultiplexing the control signal and the line switching signal, and the circuit configuration is complicated and the cost is high. there were.

[0016]

According to the present invention, there is provided a line switching system for a wireless device, comprising: a indoor unit having a duplex system;
Signal by coaxial cable between knit and outdoor unit
Is transmitted and received, and each unit
The system and the coaxial cable are switched between working and standby
In the wireless device line switching method, the outdoor unit
Each system of the indoor unit is
When switching to working or spare, the indoor unit and
Superimposed on audio signals transmitted to and received from the outdoor unit
The system switching of the indoor unit is performed by the switched line switching signal.
Configuration that can be switched to working or standby depending on the system
Can be taken .

The line switching system of the wireless device is configured such that each of the duplexed systems of the indoor unit generates a first main signal of a carrier frequency f1 and a first transmitter of a first main signal of a carrier frequency f2. a main receiver for receiving a second main signal similar signal formats, the control signal transmitter at the carrier frequency f3 produce control signals of the outdoor unit, the working
When the carrier frequency is determined based on the line switching signal.
An audio signal transmitter that generates an AM signal obtained by modulating the number f4 with an audio signal, and a power transmission unit that generates a DC power for a power supply of the outdoor unit, at least, wherein the carrier frequencies f1, f2, f3, and f4 are Each of the duplicated systems of the outdoor unit having different frequencies from each other,
A transmission head which produces a transmit high frequency signal from the second main signal, the reception head to produce a first main signal from the received high frequency signal, a control signal receiver for receiving a control signal of the outdoor unit, when the working Restores the AM modulated signal
When adjusted, together with the audio signal, the carrier frequency f
DC level above the preset threshold value
You can take the audio signal demodulator to produce Le, a structure including the at least a power receiving section for receiving the DC power for the power supply of the outdoor unit.

One of the line switching methods of the wireless device is that when the audio signal transmitter becomes a standby, the line switching signal is transmitted.
The generation of the AM modulation signal obtained by modulating the carrier frequency f4 with the audio signal based on the signal can be stopped .

The line switching method of the wireless device is based on the voice signal.
When the signal demodulator becomes standby, the AM modulation signal is supplied.
DC level below the preset threshold
It is possible to configure the resulting Le.

[0020]

In the line switching method of the wireless device,
A line switching signal of the outdoor unit generated by the indoor unit is superimposed on an audio signal and sent to the outdoor unit. Therefore, this line switching system provides transmission and reception of the AM signal of the audio signal by providing an AND gate between the existing audio signal transmitter and a carrier oscillator that generates a carrier of the modulator of the audio signal. From the stop, transmission and detection of the line switching signal can be performed . The transmission and detection of the line switching signal can be performed in about several μS, and an ideal line switching speed can be obtained. In addition, parallel-to-serial converters and serial
Since only an AND gate is required instead of the parallel converter, the circuit configuration of the line switching system is simple and economical.

[0022]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing one embodiment of a line switching system of a wireless device according to the present invention. FIG. 2 is a waveform diagram for explaining the embodiment of FIG.
(A) is a waveform of the sound signal S _vt, (b) is a waveform of the modulation signal S _m to the modulator 42 outputs, (c) is a waveform of the demodulated signal S _vr demodulator 12 occurs.

The wireless device of FIG. 1 has a configuration similar to that of the wireless device of FIG. 3 described above. Circuits having the same functions and operations are denoted by the same reference numerals, and when describing this embodiment, FIG. Descriptions of the components that do not change are omitted. It should be noted that components in FIG. 1 from which the suffix A is omitted indicate that the components with the same reference numerals in FIG. 3 are somewhat different.

First, the first indoor system 201 will be described. The line switching signal S _SW of the outdoor unit 102 is sounded.
Superimposed on the voice signal, that is characterized by sending from the audio signal transmitter 4 to the first outdoor system 301. Therefore, the control signal transmitter 3 sends only the control signal S _C to the control signal receiver 11 of the first outdoor system 301, and the control signal receiver 11 reproduces the control signal S _C to perform various operations of the first outdoor system 301. Use for control. That is, the control signal transmitter 3
Has a parallel-serial converter and a control signal receiver 11
Does not require a serial / parallel converter,
The circuit configuration is simplified and economy is achieved.

In the audio signal transmitter (VTX) 4, the transmission audio signal S _vt (see FIG. 2A) is input to the modulator 42 via the amplifier 41. The carrier oscillator 8 generates a carrier S _cw having a frequency f4, and this carrier S _cw is AND
The signal is supplied to the modulator 42 via the gate 7. When the line switching signal S _{sw is set} to the ON level, in this example, the first indoor system 201 and the first outdoor system 301 are used. When the line switching signal S _sw is at the ON level, the modulator 4
2 modulates the carrier S _cw with the transmission voice signal S _vt to generate a modulated signal S _m (see FIG. 2 (b1)). Meanwhile, the first
When the line switching signal S _sw is at the OFF level, the indoor system 201 and the first outdoor system 301 are used as spares,
Since the AND gate 7 prevents the supply of the carrier S _cw to the modulator 42, the transmission of the modulation signal S _m is stopped (FIG. 2).
(See (b2)). Although described later, you may want to make a shallower degree of modulation of the modulation signal S _m.

Further, the line switching signal S _sw is changed from the OFF level to the ON level, that is, the first indoor system 201.
When the first outdoor system 301 is switched to the current operation, the line switching signal S _sw turns the AND gate 7 from OFF to O.
N, and changes from a state in which the transmission of the modulation signal S _m is stopped to a state in which the modulation signal S _m is generated.

Further, the case where the first outdoor system 301 is in operation will be described. The input modulated signal _Sm is supplied to the demodulator 12 via the band-pass filter 64. The demodulator 12 detects the modulated signal _Sm by the detection diode 43 (half-wave rectification: that is, AM demodulation), removes the high frequency component by the capacitor 44, and outputs the detection output by the resistor 45.
(See FIG. 2 (c1)). The audio frequency component in the detection output is output as an audio signal _Svr to a predetermined device such as a telephone via the capacitor 13 and the amplifier 14.

Here, the detection output generated at the resistor 45 is
Modulated signal S _m is the carrier S _cw component because it is shallow AM modulated by the audio signal S _vt Many include a DC component of the considerable amount. The level of this DC component is compared by the comparator 16 with a criterion (threshold) Ref. When the DC level of the detection output is larger than the criterion Ref (see FIG. 2 (c1)), the comparator 16 outputs a signal indicating that the first outdoor system 301 is currently in use to the ODU10.
2 to the outdoor system switcher 18 belonging to the common part of the two. Then, the outdoor system switch 18 constituted by a logic circuit keeps the first outdoor system 301 as the active side and the second outdoor system 302 as the standby side.

On the other hand, in the first indoor system 201,
Line switching signal S _sw is OFF level or ON from the beginning
When changing from level to the OFF level, because no modulation signal S _m, the demodulator 12 is not supplied modulated signal S _m, the detection output remains at 0 DC level (FIG. 2
(C2)). In this case, the comparator 16 determines that the DC level of the detection output is smaller than the criterion Ref (see FIG. 2 (c2)), and the second outdoor system 30
The outdoor system switching signal _Stsw is _set to O
It is sent to the outdoor system switch 18 belonging to the common part of the DU 102. The outdoor system switch 18 is connected to the first
The outdoor system 301 is the spare side, and the second outdoor system 302
Is switched to the current side or the current side.

[0030] As described above, the audio signal line switching signal S _SW
By superimposing the line switching signal, the wireless device can instantaneously transmit the line switching signal S _SW to the outdoor system switch 18 without waiting for the polling period, and can achieve line switching on the order of several μS. .

[0031]

The present invention described above, according to the present invention, the duplex of
Between an indoor unit and an outdoor unit
Signals are transmitted and received between coaxial cables between
Then, each system of each unit and coaxial cable
In the line switching method of the wireless device that can be switched between the working and the standby, each of the duplicated systems of the outdoor unit is
Room that supports line switching signals for switching to standby or standby
Since the signal is superimposed on the audio signal from any system of the unit and transmitted, the transmission and detection of the line switching signal can be executed in about several μS, and there is an effect that an ideal line switching speed can be obtained.

Further, the present invention eliminates the need for a parallel-serial converter and a serial-parallel converter, such as a conventional line switching system for multiplexing a line switching signal with a control signal, and an existing circuit for an audio signal. Therefore, there is an effect that the circuit configuration of the line switching system can be simplified and economical.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a line switching system of a wireless device according to the present invention.

FIG. 2 is a waveform chart for explaining the embodiment of FIG. 1;

FIG. 3 is a configuration diagram of a line switching system of a wireless device according to the related art.

[Explanation of symbols]

 Reference Signs List 101 Indoor unit (IDU) 102 Outdoor unit (ODU) 201 First indoor system 202 Second indoor system 301 First outdoor system 302 Second outdoor system 1 Main transmitter 2 Main receiver 3 Control signal transmitter (CTX) 4 Voice Signal transmitter (VTX) 41 Amplifier 42 Modulator 5 Power transmission unit (TPS) 6a, 6b Demultiplexer 61-64 Bandpass filter 65 Low-pass filter 7 AND gate 8 Carrier oscillator 9 Transmission head 10 Reception head 11 Control signal receiver (CRX) 12 Demodulator 43 Detection diode 44 Capacitor 45 Resistor 13 Capacitor 14 Amplifier 15 Power receiving unit (RPS) 16 Comparator 17 Inverter 18 Outdoor system switch

Claims (5)

(57) [Claims] An indoor unit having a dual system.
Signal between the unit and the outdoor unit via a coaxial cable.
Transmission and reception are performed, and each system of each unit is
If the stem and the coaxial cable are switched between working and spare
In the wireless device line switching method, the outdoor unit
Each system of the indoor unit is
When switching to a room or spare,
Superimposed on the audio signal transmitted to and received from the outdoor unit
Each of the systems of the indoor unit is
A line switching method for a wireless device, characterized in that it can be switched to an active or standby mode according to the system. 2. The duplex system of the indoor unit comprises a main transmitter for generating a first main signal having a carrier frequency f1, and a second main signal having a signal format similar to that of the first main signal having a carrier frequency f2. A main receiver for receiving the signal, a control signal transmitter for generating a control signal for the outdoor unit at a carrier frequency f3, and the line switching signal when in service.
A obtained by modulating the carrier frequency f4 with an audio signal based on
An audio signal transmitter for generating an M-modulated signal; and a power transmitting unit for generating DC power for powering the outdoor unit, at least including the carrier frequencies f1, f2, f3 and f4.
Are different frequencies from each other, and each of the duplicated systems of the outdoor unit comprises a transmission head for generating a transmission high frequency signal from the second main signal, and a reception head for generating the first main signal from the reception high frequency signal. when the control signal receiver for receiving a control signal for the outdoor unit, and the audio signal when the <br/> when the current obtained by demodulating the AM modulated signal DOO
In addition, it is set in advance by detecting the carrier frequency f4.
An audio signal demodulator that produces a DC level greater than or equal to a threshold ;
2. The line switching system for a wireless device according to claim 1, further comprising at least a power receiving unit for receiving DC power for a power source of said outdoor unit. 3. When the audio signal transmitter becomes a standby,
Sounds the carrier frequency f4 based on the line switching signal.
3. The line switching method according to claim 2, wherein the generation of the AM signal modulated by the voice signal is stopped . 4. When the audio signal demodulator becomes a standby,
Is set in advance because the AM modulation signal is not supplied.
4. A line switching system for a wireless device according to claim 2, wherein a DC level lower than the threshold value is generated . 5. The system of claim 2, wherein each of said outdoor units has a dual system.
Each of the duplicated systems of the indoor unit is
When switched to working or standby, the voice signal
Working or according to the DC level based on the demodulator output.
Is switched to a spare .
5. The line switching method of the wireless device according to 2, 3, or 4 .