JP2001156706A - Wireless communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless communication system that can reduce deteriorated speech quality. SOLUTION: The wireless communication system is provided with an ordinary radio wave transmission section 15 that transmits ordinary radio waves approved in advance by the legislation, an ordinary radio wave filter 12 that passes through a voice signal with high priority and leads it to the ordinary radio wave transmission section, a very weak radio wave transmission section 16 that transmits a very weak radio wave, a very weak radio wave filter 13 that passes through a voice signal with low priority and leads it to the very weak radio wave transmission section, an ordinary radio wave reception section 17 that receives the ordinary radio wave, a very weak radio wave reception section 18 and an adder 14 that synthesises the voice signal with high priority outputted from the ordinary radio wave reception section with the voice signal with low priority outputted from the very weak radio wave reception section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication device, and more particularly to a radio communication device for transmitting and receiving voice signals in two systems, a normal radio wave and a weak radio wave, according to priority.

[0002]

2. Description of the Related Art Conventionally, a wireless communication apparatus for transmitting and receiving a voice signal between remote places has been proposed as shown in FIG.

FIG. 2 shows a block diagram of a conventional radio communication device.

In FIG. 2, radio communication devices 3 and 4 arranged between remote places transmit and receive voice signals and perform voice input / output, respectively. It comprises transmission circuits 32 and 42 for transmitting a radio wave (hereinafter referred to as “normal radio wave”) and receiving circuits 33 and 43 for receiving the normal radio wave.

[0005] The wireless communication devices 3 and 4 configured as described above.
In, when a voice is input to the communication circuit 31 of one of the wireless communication devices 3, the voice signal is converted into a voice signal in the communication circuit 31 and output to the transmission circuit 32. Here, the transmission of voice in the wireless device is limited by the provisions of the Radio Law, so the transmission circuit 32 limits the frequency band of the voice signal to a band authorized by law. After being modulated to the frequency of a normal radio wave, the radio wave is transmitted to the outside of the wireless communication device 3.

On the other hand, the normal radio wave transmitted from the other wireless communication device 4 is transmitted to the receiving circuit 3 of the one wireless communication device 3.
The received normal radio wave is demodulated and converted into an audio signal, and then output to the communication circuit 31. Then, in the communication circuit 31, the voice signal is converted into voice and output.

[0007]

However, in the conventional wireless communication device, the transmittable voice band is limited by the provisions of the Radio Law, that is, the frequency band of the voice signal is limited by the transmission circuit. Therefore, there was a problem that the sound quality was deteriorated as compared with the wired type.

The present invention has been made in order to solve the above-mentioned difficulties, and an object of the present invention is to provide a radio communication device capable of reducing deterioration of sound quality.

[0009]

In order to achieve the above object, a radio communication apparatus according to the present invention comprises: a normal radio wave transmitting section for transmitting a normal radio wave which is approved in advance by law; A normal radio wave filter that passes through the normal radio wave transmitter, a weak radio wave transmitter that transmits weak radio waves, a weak radio wave filter that passes low-priority audio signals through the weak radio wave transmitter, and a normal radio wave receiver that receives normal radio waves Unit, a weak radio wave receiving unit that receives a weak radio wave, and an adder that combines a high priority audio signal output from the normal radio wave receiving unit and a low priority audio signal output from the weak radio wave receiving unit. It is characterized by having.

According to such a radio communication device, the frequency band of an audio signal that could not be transmitted due to the limitation of the audio band that can be transmitted according to the provisions of the Radio Law is transmitted by the feeble radio wave transmitting unit, Since the radio wave is combined with the original audio signal in the receiving unit, deterioration of sound quality can be reduced.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a wireless communication device according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a wireless communication apparatus according to the present invention.

In FIG. 1, wireless communication devices 1 and 2 of the present invention arranged between remote places respectively transmit and receive voice signals and input and output voice signals.
Normal radio wave filters 12 and 22 and weak radio wave filters 13 and 2 connected in parallel to the communication circuits 11 and 21.
3 and adders 14 and 24. The normal radio wave filters 12 and 22 are connected to normal radio wave transmission units 15 and 25 having transmission circuits 15a and 25a, respectively. Have transmission circuits 16a and 26
a and the weak radio wave transmission units 16 and 26 having output adjustment circuits 16 b and 26 b are connected to each other.
4 is connected in parallel to normal radio wave receiving units 17 and 27 having receiving circuits 17a and 27a and weak radio wave receiving units 18 and 28 having receiving circuits 18a and 28a, respectively.

Here, the normal radio wave filters 12, 22
Has a function of passing only high-priority audio signals of the audio signals transmitted from the communication circuits 11 and 21 to the normal radio wave transmitting units 15 and 25, respectively. , Respectively, the normal radio wave filters 12, 2
2 is modulated into a normal radio wave, and the normal radio wave is transmitted through the transmitting circuits 15a and 25a to the radio communication device 1,
2 has a function of transmitting to the outside. Note that the normal radio wave filters 12 and 22 are low-pass filters, respectively, because the low frequency band of the audio signal is a signal with a high priority.

The weak radio wave filters 13 and 23 are
Of the audio signals transmitted from the communication circuits 11 and 21, respectively, only the low priority audio signal is transmitted to the weak radio wave transmitting unit 1.
6 and 26, and a weak radio wave transmitting unit 1
Reference numerals 6 and 26 denote weak radio wave filters 13 and 23, respectively.
Is modulated into a weak radio wave, and the weak radio wave is input to the transmission circuits 16a and 26a.
a, 26a to output adjustment circuits 16b, 2
In step 6b, the output level of the weak radio wave is adjusted and then transmitted to the outside of the radio communication devices 1 and 2. Note that the weak radio wave filters 13 and 23 are usually high-pass filters because the high frequency range of the audio signal is a signal having a low priority.

On the other hand, the normal radio wave receiving units 17 and 27 have a function of receiving the normal radio waves transmitted from the wireless communication devices 1 and 2 by the receiving circuits 17a and 27a and demodulating them into audio signals. Also, the weak radio wave receiving units 18 and 28
The reception circuits 18a and 28a receive the weak radio waves transmitted from the wireless communication devices 1 and 2 and demodulate them into audio signals.

The adders 14 and 24 respectively provide a high-priority audio signal output from the normal radio wave receiving units 17 and 27 and a low-priority audio signal output from the weak radio wave receiving units 18 and 28, respectively. And a function of synthesizing

Next, the operation of the radio communication devices 1 and 2 configured as described above will be described.

First, the communication circuit 1 of one radio communication device 1
When an audio signal is input to the audio signal 1, the audio signal is converted into an audio signal, which is an electric signal, and is output to the normal radio wave filter 12 and the weak radio wave filter 13, where the high priority audio signal and the low priority audio signal are output. Separated into audio signals. Then, when an audio signal is input to the normal radio wave filter 12, a high priority audio signal is output to the normal radio wave transmission unit 15.
Then, in the normal radio wave transmitting unit 15, after the high priority audio signal is modulated into the normal radio wave by the transmission circuit 15a,
It is transmitted to the outside of the wireless communication device 1.

In the weak radio wave filter 13, when an audio signal is input, a low priority audio signal is output to the weak radio wave transmitting unit 16. Then, in the weak radio wave transmitting unit 16, the audio signal of low priority is modulated into a weak radio wave by the transmission circuit 16 a, and the weak radio wave is transmitted to the weak radio wave transmitting unit 16.
In the output adjusting circuit 16b, the output level is adjusted to a level of a weak radio wave not specified in the Radio Law and then transmitted to the outside of the wireless communication device 1.

On the other hand, the normal radio wave transmitted from the other radio communication device 2 is received by the normal radio wave receiving section 17 of the one radio communication device 1, and is modulated by the receiving circuit 17a into a high priority audio signal. Thereafter, it is output to the adder 14. The weak radio wave transmitted from the other wireless communication device 2 is transmitted to the weak radio wave receiving unit 18 of the one wireless communication device 1.
, And after being modulated by the receiving circuit 18a into a low-priority audio signal, is output to the adder 14.

Thus, the adder 14 synthesizes the high-priority audio signal and the low-priority audio signal.
1 is transmitted. Therefore, a voice with good sound quality is output from the communication circuit 11.

In the above embodiment, transmission and reception of one radio communication device 1 is mainly described. However, the present invention is not limited to this, and the other radio communication device 2 may be used.
The same effect as described above can be obtained by transmitting and receiving data.

[0024]

As is apparent from the above description, according to the radio communication apparatus of the present invention, the radio law does not specify the high-frequency portion of the voice that cannot be transmitted due to the limitation of the voice band, according to the radio law. Since weak radio waves are used to transmit and receive wireless signals in a so-called two system, deterioration in sound quality can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a conventional wireless communication device.

[Explanation of symbols]

 12 ... Normal radio wave filter 13 ... Weak radio wave filter 14 ... Adder 15 ... Normal radio wave transmission unit 16 ... Weak radio wave transmission unit 17 ... Normal radio wave reception unit 18 ... Weak radio wave receiver

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) // H04M 9/00 H04B 7/26 Q

Claims (1)

[Claims] An ordinary radio wave transmitting unit (15) for transmitting an ordinary radio wave which is approved in advance by law, and a normal radio wave filter (1) for passing a high priority audio signal to the normal radio wave transmitting unit.
2) and a weak radio wave transmitting unit (16) for transmitting a weak radio wave
A weak radio wave filter (13) for passing a low-priority audio signal to the weak radio wave transmitting unit; a normal radio wave receiving unit (17) for receiving the normal radio wave; and a weak radio wave receiving unit for receiving the weak radio wave (18) and an adder (14) for synthesizing a high-priority audio signal output from the normal radio wave receiving unit and a low-priority audio signal output from the weak radio wave receiving unit. A wireless communication device characterized by the following.