JPH11205253A - Radio equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio equipment that detects a fault in a transmission system even when a transmission reception common use antenna and a reception exclusive antenna are mounted at an optional position such as a place at which an antenna characteristic is not deteriorated due to surrounding buildings or the like. SOLUTION: The radio equipment is provided with a reception antenna 4 that receives part of a transmission signal outputted from a transmission antenna and connects to a detection circuit and detects a fault of a transmission signal outputted from the transmission antenna 1 based on an output level of the detection circuit. A level adjustment means 20 is placed to a pre-stage of the detection circuit so as to detect the fault of the transmission signal outputted from the transmission antenna 1 independently of an installation distance between the transmission antenna 1 and the reception antenna 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a radio apparatus, and more particularly to a means for detecting a failure in a transmission system.

[0002]

2. Description of the Related Art Generally, in mobile communication requiring a large number of base stations such as a portable telephone system, an output from a local station is sent to a base station (or mobile station) radio apparatus in order to improve the efficiency of maintenance work. Many have a function of detecting an abnormality in a transmission signal. Also, in order to reduce the degradation of reception characteristics due to the fading phenomenon unique to mobile communication,
A diversity reception method is widely used in which a plurality of antennas are spatially separated and a plurality of reception signal levels output from a reception circuit connected to each antenna are compared to select an optimum reception signal.

[0003] FIG. 2 is a block diagram showing a configuration example of a base station radio apparatus in mobile communication provided with a conventional transmission signal abnormality detection function and a diversity reception system. The wireless device shown in this example has a transmitting / receiving shared antenna 1 and a transmitting / receiving duplexer 2 connected to the shared transmitting / receiving antenna 1 to separate a transmission signal and a reception signal, as a transmission / reception joint part.
And Further, as a receiving system, a first receiving unit 3 connected to the duplexer 2 for demodulating a received modulated signal, a receiving antenna 4 sequentially connected for diversity reception, and a first distribution circuit. 5 and a first band-pass filter 6 that passes only the received signal and a second receiving unit 7 that demodulates the received modulated signal, and the first receiving unit 3 and the second receiving unit 7 Each is connected to the level comparison circuit 8.

[0004] On the other hand, the transmission system includes a transmission circuit 9 that receives a modulation signal (transmission data) from a signal processing unit (not shown) and generates a modulated signal, and amplifies the generated modulated signal to a predetermined level. Power amplifier 1 to output to the second distribution circuit 11
And a circulator 12 disposed between the duplexer 2 and the second distribution circuit 11 to protect the power amplifier 10 and the like from reflected signals caused by the duplexer 1 and the duplexer 2. Consists of

Further, in order to detect an abnormality of the power amplifier 10, a part of an output signal of the power amplifier 10 is input through the second distribution circuit 11 and a first A / D converter (analog / digital conversion) is used. A) a first detection circuit 13 that supplies an output signal to the device 14, and a controller 15 having a CPU disposed between the first A / D converter 14 and the level comparison circuit 8. In order to detect an abnormality related to a transmission system from the transmission circuit 9 to the transmission / reception shared antenna 1, the transmission signal is transmitted through a second band-pass filter 16 that passes only the transmission signal connected to the first distribution circuit 5. A second detection circuit 1 that partially receives and supplies an output signal to a second A / D converter 17 connected to the controller 15
Has eight.

[0006] The wireless device shown in this example functions as follows. First, explaining the diversity reception function,
The received signal fR is guided to the first receiving unit 3 via the transmission / reception shared antenna 1 and the transmission / reception duplexer 2, demodulated there, and output to the level comparison circuit 8. In parallel with this, the reception signal fR is transmitted to the reception-only antenna 4 and the first distribution circuit 5.
And the first bandpass filter 6 that passes only the received signal
And is demodulated and output to the level comparison circuit 8. Level comparison circuit 8
Compares the levels of the two received signals fR, selects the received signal fR having a higher level, and outputs it to the signal processing unit. Therefore, since the wireless device can always perform the receiving process using a higher-level signal, it is possible to reduce the deterioration of the receiving characteristic due to the fading phenomenon.

[0007] Next, the function as a transmission system will be described. After a modulation signal (transmission data) input from a signal processing unit is formed into a modulated signal by a transmission circuit 9, the power amplifier 1
While amplifying to a desired level by 0, the second distributor 11
, A circulator 12, a transmission / reception duplexer 2, and a transmission / reception shared antenna 1 to transmit to the space. At this time, in order to detect an abnormality of the power amplifier 10, a part of the transmission signal output from the power amplifier 10 is input to the first detection circuit 13 via the second distributor 11, and demodulated here, and then the first signal is demodulated. The signal is converted into a digital signal by the A / D converter 14 and input to the controller 15. The controller 15 determines that the power amplifier 10 is out of order when the input signal level is out of the specified value range, and transmits the transmission abnormality signal 30 to the signal processing unit.

[0008] Further, in order to detect an abnormality in the transmission system from the transmission circuit 9 to the transmission / reception shared antenna 1, a part of the transmission signal transmitted from the transmission / reception shared antenna 1 to the space is received by the reception only antenna 4 and the first distribution antenna. A second detection circuit 18 via the circuit 5 and a second band-pass filter 16 for passing only a transmission signal;
The demodulation is performed here, and the second A / D converter
The signal is converted into a digital signal by 17 and input to the controller 15.
The controller 15 determines that the transmission system is out of order when the input signal level related to the transmission signal is out of the specified value range, and transmits a transmission abnormality signal 30 to the signal processing unit to report the abnormality of the transmission system. I do.

[0009] It should be noted that the transmission / reception shared antenna 1 and the reception-only antenna 4 need to be mounted at optimal positions where the antenna characteristics are not degraded in consideration of the environment of the surrounding buildings where the base station is installed. FIG. 3 is a conceptual diagram showing a typical antenna installation example in a base station. As shown in FIG. 3, the installed antennas have different distances between the antennas depending on the position of attachment to the column 40, and therefore the amount of power leakage (coupling) differs due to the difference in radio wave propagation loss.

[0010]

However, the function of detecting the abnormality of the transmission system in the above-mentioned conventional wireless device has the following problems. In other words, when trying to install the shared antenna for transmission and reception 1 and the antenna for reception only 4 in an optimal place where the antenna characteristics do not deteriorate considering only the influence of the surrounding buildings, etc., as shown in FIG. 3 depending on the place where the antenna is installed. Since the amount of power leakage between the antennas changes as described above, the amount of power leakage of the transmission signal from the transmission / reception shared antenna 1 to the reception-only antenna 4 changes from a predetermined value, and as a result, although the transmission system is normal,
Since the level of the transmission signal input to the second detection circuit 18 is out of the specified value range, the controller 15 transmits a transmission abnormality signal and causes malfunction of the abnormality detection function. Therefore, the transmission and reception shared antenna 1 and the reception only antenna 4 should be installed at a position (distance) where a predetermined amount of power leakage can be obtained, but in practice, especially in a densely populated city, the installation location of the antenna is limited, There has been such a problem that a desired amount of power leakage cannot be obtained due to deterioration of antenna characteristics due to surrounding buildings and the like. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems related to the conventional wireless device, and provides a wireless device capable of detecting an abnormality in a transmission system even if a transmission / reception antenna and a reception-only antenna are attached to arbitrary positions. The purpose is to:

[0011]

In order to achieve the above object, the invention according to claim 1 of the wireless device according to the present invention is as follows.
A wireless device that receives a part of a transmission signal output from a transmission antenna and includes a reception antenna connected to a detection circuit, and detects an abnormality of the transmission signal output from the transmission antenna based on an output level of the detection circuit. By arranging a level adjusting means in front of the detection circuit, an abnormality of a transmission signal output from the transmission antenna can be detected regardless of an installation distance between the transmission antenna and the reception antenna. The invention according to claim 2 of the wireless device according to the present invention, in the wireless device according to claim 1, the receiving signal shared via the transmitting antenna and the receiving antenna while sharing the transmitting antenna for reception, And is used to perform diversity reception.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. FIG. 1 is a block diagram showing an embodiment of a wireless device according to the present invention. The wireless device shown in this example includes, as a transmission / reception joint part, a transmission / reception shared antenna 1 and a transmission / reception duplexer 2 connected to the transmission / reception shared antenna 1 for separating a transmission signal and a reception signal. As a receiving system, a first receiving unit connected to the duplexer 2 for demodulating a received modulated signal
3, a reception-only antenna 4 sequentially connected for diversity reception, a first distribution circuit 5, a first band-pass filter 6 for passing only reception signals, and a second reception unit for demodulating a received modulated signal. And the first receiving unit 3 and the second receiving unit 7 are connected to a level comparison circuit 8, respectively.

On the other hand, the transmission system includes a transmission circuit 9 that receives a modulation signal (transmission data) from a signal processing unit (not shown) and generates a modulated signal, and amplifies the generated modulated signal to a predetermined level. Power amplifier 1 to output to the second distribution circuit 11
And a circulator 12 disposed between the duplexer 2 and the second distribution circuit 11 to protect the power amplifier 10 and the like from reflected signals caused by the duplexer 1 and the duplexer 2. Consists of

Further, in order to detect an abnormality of the power amplifier 10, a part of the output signal of the power amplifier 10 is input via the second distribution circuit 11 and a first A / D converter (analog / digital conversion) A) a first detection circuit 13 that supplies an output signal to the device 14, and a controller 15 having a CPU disposed between the first A / D converter 14 and the level comparison circuit 8. In order to detect an abnormality related to a transmission system from the transmission circuit 9 to the transmission / reception shared antenna 1, the transmission signal is transmitted through a second band-pass filter 16 that passes only the transmission signal connected to the first distribution circuit 5. A second detection circuit 1 that partially receives and supplies an output signal to a second A / D converter 17 connected to the controller 15
8 is the same as the prior art.

A feature of the present invention resides in that a variable attenuator 20 as a level adjusting means is arranged between a second band-pass filter 16 for passing only the transmission signal and a second detection circuit 18 and D / A The variable attenuator 20 is controlled by the controller 15 via a converter (digital / analog converter) 21.

The function of the wireless device according to the present invention as a receiving system or a transmitting system is the same as that of the prior art, and thus the description thereof is omitted. However, the transmitting system from the transmitting circuit 9 to the transmitting / receiving antenna 1 which characterizes the present invention. The abnormality detection function related to will be described in detail. First, when the wireless device according to the present invention is started, the power amplifier 10 is turned on and starts a transmission operation for detecting an abnormality. That is, as described above, the modulated signal (transmission data) input from the signal processing unit is formed into a modulated signal by the transmission circuit 9 and then amplified to a desired level by the power amplifier 10, and the second distributor 11 and the circulator The signal is transmitted to the space via the transmission / reception duplexer 12 and the transmission / reception shared antenna 1. At this time, in order to detect an abnormality of the power amplifier 10, a part of the transmission signal output from the power amplifier 10 is input to the first detection circuit 13 via the second distributor 11, and demodulated here, and then the first signal is demodulated. The signal is converted into a digital signal by the A / D converter 14 and input to the controller 15. The controller 15 determines that the power amplifier 10 is out of order when the input signal level is out of the specified value range, and transmits the transmission abnormality signal 30 to the signal processing unit.

Next, if the controller 15 determines that the power amplifier 10 operates normally, a part of the transmission signal transmitted from the transmission / reception shared antenna 1 to the space is received by the reception-only antenna 4 and the first distribution circuit.
5 and the second bandpass filter that passes only the transmission signal
16 and a variable attenuator 20 in which the amount of attenuation is set to zero for a reason to be described later, the signal is guided to a second detection circuit 18, where demodulation is performed, and a digital signal is further converted by a second A / D converter 17. And input to the controller 15. At this time, as described above, due to the change in the amount of power leakage between the antennas due to the mounting position of the shared antenna for transmission and reception 1 and the antenna for reception only 4,
If the input signal level to the detection circuit 18 of the second device fluctuates from a specified value (threshold having a predetermined width for abnormality determination), the controller 15 sends the level control signal via the D / A converter 21 to the level control signal. 31 is transmitted to the variable attenuator 20. As a result, the variable attenuator 20 sets the amount of attenuation so that the level of the input signal to the second detection circuit 18 becomes the specified value, and fixes this.

Therefore, even if the transmission / reception shared antenna 1 and the reception-only antenna 4 are installed at arbitrary positions and the amount of power leakage between the antennas has changed from a predetermined value, the second detection circuit is required when the wireless device is started up. Since the input signal level to 18 is set to the specified value, the input signal level to the second detection circuit 18 is monitored based on the specified value level, and if the input signal level is out of the specified value range. If this is the case, the controller 15 can determine that an abnormality has occurred in the transmission system described above, and transmit a transmission abnormality signal 30 to the signal processing unit to notify the transmission system of the abnormality.

The specified value level at the input of the second detection circuit 18 is based on the maximum distance expected as the installation interval between the transmission / reception antenna 1 and the reception antenna 4, in other words, the minimum antenna Since the power leakage between the two antennas is set assuming the power leakage between the two antennas, the power leakage between the antennas is always larger than the expected value regardless of the installation distance between the two antennas. The signal level input to the detection circuit 18 is always higher than the specified value level. Therefore, as a level adjusting means for adjusting the signal level input to the second detection circuit 18 to the specified value level, any situation can be handled with a simple configuration including only the variable attenuator 20.

As described above, since the radio apparatus according to the present invention functions, an abnormality in the transmission system can be detected even when the transmission / reception antenna 1 and the reception-only antenna 4 are mounted at arbitrary positions.

[0021]

According to the present invention, as described above, a part of the transmission signal output from the transmission / reception shared antenna is configured to be guided to the second detection circuit via the variable attenuator as the level adjusting means. Even if the common antenna and the reception-only antenna are installed at arbitrary positions, such as a place where the antenna characteristics are not deteriorated by a surrounding building or the like, it is highly effective in realizing a wireless device capable of detecting an abnormality in the transmission system.

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating an embodiment of a wireless device according to the present invention.

FIG. 2 is a functional block diagram illustrating a configuration example of a conventional wireless device.

FIG. 3 is a conceptual diagram illustrating an example of antenna installation of a base station.

[Explanation of symbols]

1, shared transmission / reception antenna 2, shared transmission / reception device 3, first receiving unit 4, reception-only antenna 5, first distribution circuit 6, first bandpass filter 7 that passes only received signals 7 ..Second receiving section 8 level comparator 9 transmitting circuit 10 power amplifier 11 second distributor 12 circulator 13 first detector 14 first A / D converter 15 ・ Controller 16 ・ ・ Second band-pass filter which passes only transmission signals 17 ・ ・ Second A / D converter 18 ・ ・ Second detection circuit 20 ・ ・ Variable attenuator ( Level adjustment means) 21D / A converter 30 Transmission abnormal signal 31 Level control signal

Claims (2)

[Claims] A reception antenna connected to a detection circuit while receiving a part of a transmission signal output from a transmission antenna, and detecting an abnormality of the transmission signal output from the transmission antenna based on an output level of the detection circuit. In the wireless device to be detected, by arranging a level adjusting unit in front of the detection circuit, regardless of the installation distance between the transmitting antenna and the receiving antenna, it is possible to detect an abnormality of a transmission signal output from the transmitting antenna. A wireless device, comprising: 2. The radio apparatus according to claim 1, wherein the transmission antenna is shared for reception, and diversity reception is performed using reception signals respectively guided through the transmission antenna and the reception antenna.