JPH09284237A - Non-regenerative alarm transmitter and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alarm transmitter and its method with a comparatively simple and inexpensive configuration without the need for alarm monitor MO DEM panel or the like. SOLUTION: A distribution circuit 2 branches an intermediate frequency signal from a reception radio frequency conversion panel 1 into two. A changeover circuit 3 receives one branched intermediate frequency signal, a changeover control signal, and an oscillation signal from a voltage controlled oscillator 8, and outputs the one branched intermediate frequency signal or the oscillation signal as a switching signal and a transmission frequency conversion panel 4 applies the switching signal with the intermediate frequency into a radio frequency. A squelch decision circuit 5 inputs the other branched intermediate frequency signal an discriminates whether or not the signal is a desired signal. Furthermore, a D/A converter circuit 6 connected to a voltage controlled oscillator is provided and an output voltage from the D/A converter circuit 6 is changed depending on the kind of each alarm and the carrier frequency is changed to transfer the alarm signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-regenerative repeater type alarm transmission device and method used in digital wireless communication.

[0002]

2. Description of the Related Art A non-regenerative repeater system in a digital wireless communication system using microwaves is low because it does not require a demodulation board for demodulating a modulated signal to be transmitted and discriminating and reproducing it into a digital signal, and a modulation board for inverse conversion thereof. This is effective for power consumption and simplification of relay stations.

On the other hand, on the other hand, the auxiliary signal for alarm monitoring of the non-regenerative repeater station is an analog service channel (A
SC) signals, and various methods for that have been proposed.

For example, in Japanese Examined Patent Publication No. 2-206239 (hereinafter referred to as "prior art 1"), in order to speed up the monitoring and to simplify the configuration of the non-regenerative relay station, the non-regenerative relay station is used as the station. Information is FSK-modulated at a certain frequency, the wireless carrier is FM-modulated with this FSK-modulated signal and transmitted using an ASC signal, and the monitoring information is collected by a monitoring device at a certain terminal station. A method has been proposed in which boring is performed between the monitoring devices of the terminal stations by using a relatively high-speed digital service channel (DSC) signal.

In addition, Japanese Patent Publication No. 58-134545 (hereinafter referred to as "prior art 2") is not limited to the non-regenerative repeater, but has a configuration in which a supervisory signal is transmitted using an ASC signal. In order to secure a redundant system of signals, we have proposed a method of sending a carrier wave when a device fails.

Although these technologies use ASC signals as supervisory signals, Akinaga et al. '95 Spring Electronic Information Communication Society General Conference All B534, "4-5-6G-150M system non-regenerative repeater wireless transceiver" In the presentation entitled "4,5,6G-150M-E system non-regenerative repeaterless size transmitter / receiver" (hereinafter referred to as "prior art 3") in B535, a monitoring signal is used. A method using a modulation / demodulation board for supervisory control has been reported.

This is a multi-carrier transmission system for transmitting a data signal by using modulated signals of three intermediate frequencies for one radio frequency, and a frequency between these three intermediate frequencies is used as a supervisory signal. In this method, a DSC signal is quadrature phase modulated and transmitted and received. FIG. 9 shows the state of the spectrum at this time. Here, FIG. 9 is a diagram showing the relationship between the multi-carrier and the band for line monitoring. In FIG. 9, a band 52 for line monitoring is formed between main signal multicarriers 51.

[0008]

In the method of transmitting the supervisory signal using the ASC signal proposed in the above-mentioned prior arts 1 and 2, the C / N of the reproduced carrier wave is demodulated in the demodulation board for identifying and reproducing the data signal. There is a problem that (Carrier to Noise ratio) deteriorates and the bit error rate deteriorates.

The reason for this is as follows. AS
Since the C signal is the FM modulation signal for the carrier wave, this FM modulation signal becomes a jitter component of the reproduced carrier wave, that is, a noise component for the demodulation board. Therefore, the loop band of the demodulation board must be determined optimally.

The carrier wave synchronizing circuit of the demodulation board is a general PLL.
It is a (Phase Lock Loop) circuit, and a second order lag lead filter is used in the low frequency reactor wave circuit of this PLL.

In this case, this loop follows up to the frequency f ₀ at which the loop gain becomes zero. Also, the frequency f ₀ cannot be narrowed too much, because the loop must operate in accordance with the frequency fluctuation due to the ASC signal. This means that from the viewpoint of the reproduced carrier, the noise component up to the frequency f ₀ is not removed, so that C /
N gets worse.

The second problem is that in order to improve the S / N (Signal to Noise Ratio) of the demodulated signal of the ASC signal, the frequency stability of the carrier frequency on the transmission side must be improved. That is, the ASC signal changes the frequency of the carrier wave and transfers the information, so that the frequency fluctuation of the carrier wave on the transmission side becomes a noise component in the ASC signal.

This frequency stability is expensive because it is necessary to improve the frequency stability of the carrier at either the intermediate frequency or the radio frequency.

In the prior art 3, it is reported that a modulation / demodulation board for circuit monitoring is provided and the band between multi-carriers is used. However, this method has a drawback that it cannot be used unless the multi-carrier method is used because only the band between the multi-carriers can be used.

Even if the system used is a multi-carrier system, the signal for supervisory control must be separated, so a very narrow band (about 210 k in this paper) is used.
The band pass filter (BPF) of b) is required. Also,
Since the ratio band (bandpass width / center frequency) is quite small, it is difficult to realize, the amount of attenuation is large, and it is very expensive.

In addition, a modulation / demodulation board must be mounted to transmit this supervisory signal, which is expensive.

Therefore, the technical problem of the present invention is that a non-regenerative repeater station can be realized with a relatively simple and inexpensive structure by eliminating the need for an ASC signal or an alarm monitoring modulation / demodulation board at another frequency for alarm transmission / monitoring. (EN) Provided is a non-regenerative relay alarm transmission device and method.

[0018]

In order to solve the above-mentioned technical problem, the non-regenerative repeating alarm transmission device of the present invention converts the frequency of the received signal from a radio frequency to an intermediate frequency signal and outputs it. Receiving frequency converting means for outputting the intermediate frequency signal to the first intermediate frequency signal and the second intermediate frequency signal.
Distribution means for branching and outputting to the intermediate frequency signal of
Squelch determining means for determining whether the received signal is a desired signal by inputting the second intermediate frequency signal and outputting a squelch control signal; oscillating means for performing voltage control type oscillation and outputting an oscillation signal; Switching means for outputting either one of the input first intermediate frequency signal or the oscillation signal as a switching signal in response to a switching control signal composed of a squelch control signal; A non-regenerative repeater equipped with a transmission frequency conversion means for converting a frequency to a radio frequency, further comprising:
A digital-analog conversion means connected to the oscillating means is provided, and the alarm is transferred by changing the output voltage of the digital-analog conversion means according to the type of each generated alarm and changing the frequency of the carrier wave. It is characterized by being.

Further, in the alarm transmission method of non-regenerative relay of the present invention, the alarm transmission of the non-regenerative relay station of the demodulation board for discriminating and reproducing the frequency signal of the squelch signal in the circuit configuration including at least one non-regenerative relay station. The feature is that the alarm of the non-regenerative station is recognized by monitoring the phase control voltage of the carrier synchronization circuit.

Further, in the alarm transmission method of non-regenerative relay according to the present invention, the received signal is converted from the radio frequency to the intermediate frequency, the signal is branched into two and the carrier synchronizing circuit is connected to one of the outputs, and the phase control voltage is monitored. By doing so, the alarm of the non-reproducing station is recognized.

Further, according to the alarm transmission method of the non-regenerative relay station of the present invention, the received alarm of the non-regenerative relay station is taken into the digital-analog conversion circuit and the frequency of the carrier wave is set in the circuit configuration including at least one non-regenerative relay station. The feature is that the alarm is transferred by changing it.

Further, in the alarm transmission method of non-regenerative relay according to the present invention, a circuit configuration including at least one non-regenerative relay station is used, and the alarm of the non-regenerative relay station received by the regenerative relay station is utilized by using the digital service channel. It is characterized by forwarding alarms.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a non-regenerative relay alarm transmission device according to an embodiment of the present invention. Referring to FIG. 1, a non-regenerative relay alarm transmission device according to an embodiment of the present invention includes a reception radio frequency conversion board 1 as reception frequency conversion means, a distribution circuit 2 as distribution means, and switching as switching means. Circuit 3, transmission radio frequency conversion board 4 as transmission frequency conversion means, squelch determination circuit 5 as squelch determination means, and digital-analog (D / A) conversion as digital-analog (D / A) conversion means. Circuit 6
And a logical sum (OR) circuit 7, and a voltage controlled oscillator 8 (VCO) as an oscillating means.

Here, the radio frequency signal RF received by the antenna is received by the reception radio frequency conversion board 1 at the radio frequency R.
F is converted into a signal of intermediate frequency IF. The converted signal IF is divided into a first intermediate frequency signal IF ₁ and a second intermediate frequency signal IF ₂ by the distribution circuit 2, and the first intermediate frequency signal IF ₁ is squelch determination circuit 5, The second intermediate frequency signal IF ₂ is input to the switching circuit 3, respectively.

The logical value "H" is input to the OR circuit 7 as the alarm RX ALM of the reception radio frequency conversion board 1.

The first intermediate frequency signal I from the distribution circuit 2
F ₁ is input to the switching circuit 3. This switching circuit 3
For example, when the output of the OR circuit 7 is logic "H", the output of the distribution circuit 2 is output, and when it is logic "L", the oscillation signal Of of the voltage controlled oscillator 8 is output.

The output of the switching circuit 3 is input to the transmission radio frequency conversion board 4, frequency-converted from the intermediate frequency IF to a radio frequency signal RF, and output to the antenna.

The output of the second intermediate frequency signal IF ₂ from the distribution circuit 2 is input to the squelch determination circuit 5.
The squelch determination circuit 5 discriminates whether or not the input signal satisfies a predetermined squelch condition, and if the squelch condition is satisfied, the squelch control signal SQL CONT is set to a logic "H" and the OR circuit 7 and D / A
Input to the conversion circuit 6.

Here, the squelch determination circuit 5 will be described with reference to FIGS.

2 and 3 are diagrams showing various examples of the squelch determination circuit. Referring to FIG. 2, an example of the squelch determination circuit includes a bandpass filter 14 and a detection circuit 15
And a discrimination circuit 16.

Referring to FIG. 3, another example of the squelch determination circuit includes a delay circuit 17, a multiplication circuit 18, a low pass filter 19, a detection circuit 20 and a discrimination circuit 21.
As the squelch determination condition, for example, in the case of a decrease in reception input or digital wireless communication, extraction of its clock component can be selected.

Returning to FIG. 1, the D / A conversion circuit 6 inputs an input digital signal (squelch control signal SQLT CONT and alarm RX ALM) and outputs an analog voltage CONT proportional to this digital signal. This analog voltage CONT is input to the voltage controlled oscillator 8 to change its frequency. In other words, when there are many alarms that occur, the analog voltage also increases and the deviation from the normal frequency increases. An alarm can be transferred by identifying this frequency deviation on the receiving side.

Next, the identification of this alarm will be described.
4 and 5 are block diagrams showing various examples of the alarm discrimination circuit. In FIGS. 4 and 5, the same components as those in FIG. 1 are given the same numbers.

Referring to FIG. 4, the signal received by the antenna is converted by the reception radio frequency conversion board 1 from the radio frequency RF to the intermediate frequency IF '. The converted signal is branched into two by the distribution circuit 2 to generate the first intermediate frequency signal I.
F ₁ ′ is the carrier synchronization circuit 9 and the second intermediate frequency signal I
F ₂ ′ is input to the switching circuit of the transmitter in the case of a non-regenerative repeater station, and to the demodulation board in the case of one terminal station / regenerative repeater station.

The carrier synchronization circuit 9 has its phase control signal A
The PC signal is output and input to the analog / (slash) digital conversion circuit 10. Since this phase control signal APC signal is a signal proportional to the frequency deviation,
By the A / D conversion by the / D conversion circuit, the alarm of the non-regenerative relay station can be identified.

The alarm identifying operation of FIG. 5 is similar to that of FIG. However, in the case of FIG. 5, the carrier synchronization circuit 9
Is built in the demodulation board 11, so as shown in FIG.
It is not necessary to have a separate configuration, and the phase control signal APC signal in the demodulation board 11 may be output for identification.

6 to 8 show a plurality of non-reproducing stations 30,3.
FIG. 3 is a diagram showing an example in which 0 ′ is connected in series between the terminal stations 101. 6 to 8, the same components as those in FIGS. 1, 4, and 5 are given the same numbers. The terminal station 101 and the non-reproducing stations 30, 30 'are
The non-reproduction stations 30 or 30 'are also connected by radio signals 32 and 104, respectively.

FIG. 6 is basically the same as the case of FIG. 1 because the carrier synchronization circuit 9 and the analog-digital conversion circuit 10 shown in FIG. 4 are added to the example of FIG. The description is omitted.

In FIG. 7, a voltage-controlled oscillator 8 is used as the intermediate frequency oscillator of the modulation board 12, and the alarm is transferred by using the voltage obtained from the alarm as the control voltage.

FIG. 8 shows a configuration in which the non-reproducing station alarm detected by the configuration of FIG. 4 is input to the code processing board 13 and the alarm is transferred using the DSC signal.

[0042]

As described above, in the non-regenerative alarm transmission device and method of the present invention, the squelch function, which originally has a function, is used to perform alarm transmission at that frequency. Therefore, an ASC signal for alarm transmission / monitoring and a modulation / demodulation board for alarm monitoring at another frequency are not required, and a non-regenerative repeater station can be realized with a relatively simple and inexpensive configuration.

[Brief description of drawings]

FIG. 1 is a block diagram showing a non-regenerative relay alarm transmission device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a squelch determination circuit in FIG.

FIG. 3 is a block diagram showing another example of the squelch determination circuit in FIG.

FIG. 4 is a block diagram showing an alarm transmission device according to a second embodiment of the present invention.

FIG. 5 is a block diagram showing an alarm transmission device according to a third embodiment of the present invention.

FIG. 6 is a diagram showing an example in which a plurality of stations including a non-reproducing station according to the embodiment of the present invention are connected in series.

FIG. 7 is a diagram showing another example in which a plurality of stations including a non-reproducing station according to the embodiment of the present invention are connected in series.

FIG. 8 is a diagram showing another example in which a plurality of stations including a non-reproducing station according to the embodiment of the present invention are connected in series.

FIG. 9 is a diagram of a multi-carrier spectrum.

[Explanation of symbols]

 1 reception radio frequency conversion board 2 distribution circuit 3 switching circuit 4 transmission radio frequency conversion board 5 squelch judgment circuit 6 digital / analog (D / A) conversion circuit 7 logical sum (OR) circuit conversion circuit 8 voltage controlled oscillator (VCO) 9 carrier wave synchronization circuit 10 analog / digital (D / A) conversion circuit 11 demodulation board 12 modulation board 13 code processing board 14 band pass filter 15 detection circuit 16 identification circuit 17 delay circuit 18 multiplication circuit 19 low pass filter 20 detection circuit 21 Identification circuit

Claims (8)

[Claims] 1. A reception frequency conversion means for converting a frequency of a received signal from a radio frequency to an intermediate frequency signal and outputting the same, and an output of the intermediate frequency signal for outputting a first intermediate frequency signal and a second intermediate frequency signal. And a squelch determining means for determining whether or not the received signal is a desired signal by inputting the second intermediate frequency signal and outputting a squelch control signal, and a voltage control type An oscillating unit that oscillates and outputs an oscillating signal, and a switching unit that outputs either one of the input first intermediate frequency signal or the oscillating signal as a switching signal according to a switching control signal composed of the squelch control signal. And a transmission frequency conversion means for converting the intermediate frequency to the radio frequency by using the switching signal as an input. A digital-analog conversion means connected to the means, and is configured to transfer the alarm by changing the output voltage of the digital-analog conversion means according to the type of each alarm generated and changing the frequency of the carrier wave. Non-regenerative relay alarm transmission device characterized by: 2. The non-regenerative relay alarm transmission device according to claim 1, wherein the reception frequency conversion means outputs an alarm signal when the radio frequency signal includes an alarm, and the switching means. Outputs either one of the first intermediate frequency signal or the oscillation signal as a switching signal according to the alarm signal, and the digital-analog conversion means is based on the squelch control signal and the alarm signal. A non-regenerative relay alarm transmission device characterized in that the output voltage is changed by means of the above. 3. The non-regenerative relay alarm transmission device according to claim 1 or 2, wherein the squelch determination means includes a bandpass filter, a detection circuit, and an identification circuit in series. Non-regenerative relay alarm transmission device. 4. The alarm transmission device of non-regenerative relay according to claim 1 or 2, wherein the squelch determination means is the second
Circuit for inputting the signal of the intermediate frequency, a multiplication circuit for multiplying the signal of the second intermediate frequency and the output of the delay circuit, and a low-pass filter connected in series to the multiplication circuit, respectively. And a detection wave circuit and an identification circuit. 5. A circuit configuration including at least one non-regenerative repeater station, by monitoring the phase control voltage of a carrier synchronization circuit of a demodulation board for identifying and reproducing the frequency signal of a squelch signal for alarm transmission of the non-regenerative repeater station. , A non-regenerative relay alarm transmission method characterized by recognizing an alarm of a non-regenerative station. 6. An alarm of a non-regenerating station is recognized by converting a received signal from a radio frequency to an intermediate frequency, branching into two, connecting a carrier synchronizing circuit to one output, and monitoring the phase control voltage. A non-regenerative relay alarm transmission method characterized by the above. 7. A circuit configuration including at least one non-regenerative relay station, wherein the received alarm of the non-regenerative relay station is taken into a digital / analog conversion circuit, and the alarm transfer is performed by changing the frequency of the carrier wave. Non-regenerative relay alarm transmission method. 8. A non-regenerative relay having a circuit configuration including at least one non-regenerative relay station, wherein the alarm of the non-regenerative relay station received by the regenerative relay station is transferred using a digital service channel. Alarm transmission method.