JP3999429B2 - Simplex radio - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a simplex radio in which opposite radios alternately transmit and receive at one frequency, and relates to a simplex radio that can easily perform radio communication by switching between frequency and transmission output. .
[0002]
[Prior art]
Conventionally, the simplex wireless communication by Press Talk is a method in which the opposite wireless devices perform communication alternately using radio waves of the same frequency for both transmission and reception, and are currently used for commercial wireless, for example.
FIG. 4 is a schematic configuration diagram showing an example of a conventional simplex wireless communication device using Press Talk. When performing communication, two or more wireless devices are used for communication.
As shown in the figure, the radio apparatus includes a transmission including an antenna 70, a high frequency band pass filter 71, an antenna switch 72, a transmission power amplifier 74, a mixer 75, an intermediate frequency band pass filter 76, and an amplifier 77. Unit 73, signal generation unit 78, low noise amplifier 80, mixer 81, intermediate frequency bandpass filter 82 and amplifier 83, reception unit 79, control unit 84, microphone 85, press switch 86, speaker 87.
Here, for example, the operation of the radio when the radio having the above-described configuration is arranged in the base station and the terminal and communication is performed using the same frequency f4 as the transmission / reception frequency is as follows.
[0003]
In FIG. 4, when the press switch 86 of the radio on the base station side is pressed, the antenna switch 72 connects the output circuit of the high-frequency bandpass filter 71 to the transmission power amplifier 74. The audio signal output from the microphone 85 is modulated by the control unit 84, amplified by the amplifier 77, band-limited by the intermediate frequency bandpass filter 76, and then mixed with the high-frequency signal from the signal generation unit 78 by the mixer 75. It is mixed and converted to frequency f4. Further, this signal is amplified to a predetermined power by the transmission power amplifier 74, and unnecessary waves are removed by the high frequency band pass filter 71 via the antenna switch 72, and then transmitted from the antenna 70.
The radio wave having the frequency f4 transmitted from the base station is received by a radio having the same configuration installed in the terminal. The antenna switch 72 connects the output circuit of the high-frequency bandpass filter 71 to the low-noise amplifier 80 when the terminal radio is not normally pressing the press switch 86.
The radio wave having the frequency f4 received by the antenna 70 is subjected to removal of unnecessary waves other than the predetermined band by the high frequency band pass filter 71, amplified by the low noise amplifier 80, and mixed with the high frequency signal from the signal generating unit 78 in the mixer 81. The frequency is converted to an intermediate frequency signal.
The frequency-converted signal is band-limited by the intermediate frequency band-pass filter 82, amplified by the amplifier 83, demodulated into a voice band by the control unit 84, signal-processed, and then output as a sound from the speaker 87.
When transmitting from the terminal and receiving at the base station, communication is performed in the same procedure as described above.
[0004]
[Problems to be solved by the invention]
However, since the simplex radio having the above-described configuration performs one-way communication using the same frequency for transmission and reception, the radio is always limited to one application. For example, as a radio for business use in public institutions, etc., it is used for communication with terminals in the area, etc. as a radio for wide communication with an output of about 5 W that can cover an area with a radius of 20 to 30 km with one base station. .
Therefore, when communication is performed between terminals in a specific small area at a work site or the like using the base station for such applications, radio waves more than necessary are radiated over a wide area, and other wireless devices in the vicinity Will be adversely affected.
To deal with this problem, it may be possible to operate separate frequencies for wide area communication and small area communication on the same wireless device. For example, if a certain terminal is set to a frequency for small area communication, There was a problem that information such as simultaneous notification using a frequency for wide area communication could not be received.
In addition, as a method of performing wireless communication in a specific small area, a method of preparing a wireless device for another small area separately from a wireless device for wide area communication or a method of configuring the wireless device in a dual band can be considered. However, there was a problem of extra costs.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a radio that can transmit and receive two different frequencies simultaneously with a single radio with a simple configuration. To do.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the invention of claim 1, the communication frequency is a simplex radio that can be changed to the first and second frequencies, and the receiving unit receives the second received by the antenna. Received frequency conversion means for converting a received signal having a frequency into an intermediate frequency signal having a third frequency, IF bandpass filter means for limiting the band of each of the first frequency and the third frequency, and received by an antenna A reception signal distribution means for directly outputting a reception signal of a first frequency to the IF bandpass filter means; a signal combining means for guiding an output signal from the reception frequency conversion means to the IF bandpass filter means; and the IF band A / D conversion means for converting the output of the pass filter means into a digital signal, and digital for extracting a predetermined channel signal from the digital signal from the A / D conversion means Comprising a filter means, a band-pass filter means for extracting a first frequency from the output of the IF bandpass filter means, and comparing means for comparing the predetermined value set in advance and the output signal level of the band-pass filter means , when said direction of the output level of the band-pass filter means is small maintains the receivable state by the second frequency by controlling said digital filter means, when towards the output level of the band-pass filter means is large the The digital filter means is controlled to shift to a reception enabled state at the first frequency.
In the invention of claim 2, in simplex type radio of claim 1, and a D / A converting means for converting the de-Ijitaru modulated signal into an analog signal, converts the frequency of the modulation signal of the analog high-frequency signal a transmission frequency converter means comprising a signal generator and a frequency mixing unit for, a transmission section and a transmission power amplification unit, in a state capable by that receive the first frequency, before Symbol transmission signal generating unit of the frequency converter is supplied to the frequency mixing unit high-frequency signals required to transmit a radio wave corresponding to the first frequency, in a state capable by that receiver in the second frequency, supplying a high frequency signal necessary for signal generation unit of the transmission frequency converting means for transmitting a radio wave corresponding to the second frequency to the frequency mixing unit, it is characterized.
Further, in the invention of claim 3, in simplex type radio apparatus according to claim 2, wherein the transmission power amplifying means amplifying degree is formed by the variable power amplifier is controlled, the output level of the variable power amplifier The state in which transmission / reception at the first frequency is possible is different from the state in which transmission / reception at the second frequency is possible.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on embodiments shown in the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of a radio according to the present invention.
As shown in the figure, the wireless device includes a broadband antenna 1, a high-frequency bandpass filter 2 having a plurality of frequency band filter units, an antenna switch 3, a variable transmission power amplifier 41, a mixer 42, and an intermediate frequency. A transmission unit 4 including a bandpass filter 43, an amplifier 44, a D / A converter 45, and a digital filter 46, an intermediate frequency bandpass filter 55 having a low noise amplifier 51, a mixer 52, and a plurality of channel filter units, and a low noise A receiving unit 5 comprising an amplifier 56, an A / D converter 58, a digital filter 59, a band pass filter 60, signal distributors 53 and 57 for outputting a signal in a specific frequency band to the secondary side, and a signal combiner 54; , A signal generator 6, a controller 7, a microphone 8, a press switch 9, and a speaker 10.
And when communicating, the radio | wireless machine of the said structure arrange | positions as a base station or a terminal unit, and communicates.
[0007]
FIG. 2 is an example of an operation mode in which the wireless device having the above configuration is used as a business wireless base station and a plurality of terminals. In the figure, the frequency for wide area communication between the base station 11 and the terminals 12, 13, 14 and 15 is, for example, f1 in the 150 MHz band, and the frequency for small area communication between the terminals 12, 13 is, for example, f2 in the 400 MHz band. Further, the frequency for small area communication between the terminals 14 and 15 is assumed to be f3 in the 400 MHz band, for example.
At this time, the antenna 1 can transmit and receive signals of frequencies in the 150 MHz band and the 400 MHz band, and the high frequency band pass filter 2 has a filter function for predetermined frequency bands of the 150 MHz band and the 400 MHz band, respectively. Furthermore, each of the signal distributors 53 and 57 outputs a signal having a frequency f1 in the 150 MHz band to the secondary side.
In the above configuration, a case where inter-terminal communication is performed using a frequency f2 in the 400 MHz band in a small area between the terminals 12 and 13 will be described.
[0008]
When the press switch 9 of the terminal 12 is pressed, the antenna switch 3 connects the output circuit of the high-frequency bandpass filter 2 to the variable transmission power amplifier 41. The audio signal output from the microphone 8 is digitally modulated by the control unit 7, channel generation is performed by the digital filter 46, and the analog signal is converted by the D / A converter 45.
This analog signal is amplified by the amplifier 44, and unnecessary waves are removed by the intermediate frequency band-pass filter 43. Then, the analog signal is mixed with the high frequency signal from the signal generator 6 in the mixer 42 and converted into a high frequency signal of frequency f2. Further, after being amplified to a predetermined power by the variable transmission power amplifier 41, unnecessary waves are removed by the high frequency band pass filter 2 through the antenna switch 3, and then transmitted from the antenna 1. At this time, the variable transmission power amplifier 41 is set to a low power mode, for example, an amplification degree of about 100 mW by a control signal from the control unit 7 in order to perform small area communication.
[0009]
A transmission radio wave having a frequency f2 transmitted from the terminal 12 is received by the terminal 13. In the terminal device 13, the antenna switch 3 connects the output circuit of the high-frequency bandpass filter 2 to the low noise amplifier 51 when the press switch 9 is not normally pressed.
The radio wave signal having the frequency f2 received by the antenna 1 is amplified by the low noise amplifier 51 via the antenna switch 3 after unnecessary waves other than the predetermined band are removed by the filter unit of the 400 MHz band of the high frequency band pass filter 2. Is done. Further, the mixer 52 mixes the high-frequency signal from the signal generator 6 and converts it to an intermediate frequency signal having the frequency f02. The intermediate frequency signal of f02 is band-limited by the intermediate frequency bandpass filter 55 via the signal combiner 54.
[0010]
FIG. 3 is a filter characteristic diagram of the intermediate frequency bandpass filter 55. As shown in the figure, the intermediate frequency band pass filter 55 is widened to accommodate a plurality of narrow band channels of 150 MHz. For example, f1, f02, f03 each having a bandwidth of about 20 kHz. , And can accommodate four signals in the f04 band, and has a pass band width of about 100 kHz as a whole.
The intermediate frequency signal band-limited by the f02 band filter of the intermediate frequency band pass filter 55 is amplified by the low noise amplifier 56 and then converted to a digital signal by the A / D converter 58. The digital signal is channel-separated by the digital filter 59, demodulated into a voice band by the control unit 7, subjected to signal processing, and then output from the speaker 10 as voice.
Communication is performed in the same procedure when transmitted from the terminal 13 and received by the terminal 12.
[0011]
The terminals 12 and 13 can receive the wide-area communication radio wave having the frequency f1 in the 150 MHz band emitted from the base station 11 by always performing the following operation even during the above-described call.
The radio wave having the frequency f 1 emitted from the base station 11 is received by the antenna 1 of the terminal 12 or the terminal 13 and input to the intermediate frequency bandpass filter 55 via the signal distributor 53. The received signal from which the unnecessary wave outside the band is removed by the f1 band filter of the intermediate frequency bandpass filter 55 is amplified by the low noise amplifier 56, converted into a digital signal by the A / D converter 58, and the signal. The signal is input to the band pass filter 60 via the distributor 57.
The signal input to the bandpass filter 60 is input to the control unit 7 after removing unnecessary waves other than f1. In the control unit 7, the received electric field strength at the frequency f1 is measured, and when the receivable electric field strength is confirmed, the control unit 7 changes the setting channel of the digital filter 59 from f2 to f1. As a result, the signal of the frequency f1 changed to a digital signal by the A / D converter 58 is channel-separated by the digital filter 59, demodulated into a voice band by the control unit 7, and output from the speaker 10 as voice.
[0012]
When the terminal 12 or 13 responds to a report from the base station 11, the channel generation function of the digital filter 46 is switched from f2 to f1 by the control signal from the control unit 7, and the output of the variable transmission amplifier 41 is further switched. The output is changed to a predetermined wide area communication output (for example, about 5 W), and the transmission frequency is set to f1 by controlling the oscillation frequency of the signal generator 6. When the terminal 12 or 13 depresses the press switch 9, the antenna switch 3 connects the output circuit of the high-frequency bandpass filter 2 to the variable transmission power amplifier 41.
Thereafter, in the same manner as described above, the mixer 42 mixes the high-frequency signal from the signal generator 6 and converts it to the frequency f1 of the 150 MHz band, and further amplifies it to a predetermined power by the variable transmission power amplifier 41. This transmission signal is transmitted from the antenna 1 via the antenna switch 3 with unnecessary waves removed by the 150 MHz band filter section of the high-frequency bandpass filter 2.
By receiving the transmission radio wave, the base station 11 can receive a response signal from the terminal 12 or the terminal 13.
Similarly to the above, the terminals 14 and 15 that perform terminal-to-terminal communication using radio waves with the frequency f3 can receive base station radio waves with the frequency f1 and respond with the frequency f1.
[0013]
【The invention's effect】
As described above, according to the wireless device of the present invention, the reception unit converts the reception unit into the intermediate frequency signal by the superheterodyne method and the reception circuit that can directly receive without frequency conversion, and transmits By using a variable transmission power amplifier capable of adjusting transmission power for wide area communication and small area communication, it is possible to simultaneously receive two different frequencies with a single radio unit. Wireless communication over a wide area such as wireless communication and simultaneous communication can be performed simultaneously.
As described above, the present invention can greatly contribute to providing a multipurpose radio to a user at a low cost.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a radio according to the present invention.
2 is a diagram showing an example of in-band frequency allocation of a reception intermediate frequency band pass filter 55 in FIG. 1. FIG.
FIG. 3 is a schematic diagram showing an example of an operation mode using the wireless device of the present invention.
FIG. 4 is a schematic configuration diagram showing an example of conventional simplex wireless communication.
[Explanation of symbols]
(Related to the present invention)
1. ・ Antenna, 2. ・ High frequency band pass filter, 3. ・ Antenna switch,
4 .... Transmission unit, 5 .... Reception unit, 6 .... Signal generation unit, 7 .... Control unit,
8 ・ Microphone, 9 ・ Press switch, 10 ・ Speaker,
11 .. Base station 12, 12, 14, 15... Terminal 41.. Variable transmission power amplifier 42.
43. ・ Intermediate frequency bandpass filter, 44 ・ ・ Amplifier,
45..D / A converter, 46..Digital filter, 51..Low noise amplifier,
52..Mixer, 53..Signal distributor, 54..Signal combiner,
55. ・ Intermediate frequency bandpass filter, 56. ・ Low noise amplifier,
57..Signal distributor, 58..A / D converter, 59..Digital filter,
60 .. band pass filter,
(Related to the prior art)
70 .. Antenna, 71 .. High frequency band pass filter,
72 .. Antenna switcher 73. Transmitter 74 74 Transmit power amplifier
75..Mixer, 76..Intermediate frequency bandpass filter, 77..Amplifier,
78..Signal generator, 79..Receiver, 80..Low noise amplifier,
81..Mixer, 82..Intermediate frequency bandpass filter, 83..Amplifier,
84..Control part, 85..Microphone, 86..Press switch,
87 ・ ・ Speaker

Claims (3)

A simplex radio that can change the communication frequency to the first and second frequencies ,
The receiver
Receiving frequency conversion means for converting a received signal of the second frequency received by the antenna into an intermediate frequency signal of the third frequency;
IF bandpass filter means for performing band limitation on each of the first frequency and the third frequency;
Received signal distribution means for directly outputting the received signal of the first frequency received by the antenna to the IF bandpass filter means;
Signal combining means for guiding the output signal from the reception frequency converting means to the IF bandpass filter means;
A / D conversion means for converting the output of the IF bandpass filter means into a digital signal;
Digital filter means for extracting a predetermined channel signal from the digital signal from the A / D conversion means;
Bandpass filter means for extracting a first frequency from the output of the IF bandpass filter means;
Comparing means for comparing the output signal level of the bandpass filter means with a predetermined value set in advance,
When the output level of the band-pass filter means is smaller, the digital filter means is controlled to maintain a receivable state at the second frequency,
When the output level of the band-pass filter means is larger, the digital filter means is controlled to shift to a receivable state by the first frequency .
Simplex-type radio characterized by that. The simplex type radio,
A D / A converting means for converting the de-Ijitaru modulated signal into an analog signal,
A transmission frequency converting means comprising a signal generating unit and a frequency mixing unit for converting the analog modulation signal into a high frequency signal ;
Transmission power amplification means ;
Comprising a transmitter with
In a state capable of receiving that by the first frequency, the signal generator of the prior Symbol transmission frequency converter means supplying a high-frequency signal necessary for transmitting a radio wave corresponding to the first frequency to the frequency mixing unit And
In a state capable by that receiver in the second frequency, the signal generator of the transmission frequency converting means supplies a high-frequency signal necessary for transmitting a radio wave corresponding to the second frequency to the frequency mixing unit to,
The simplex radio according to claim 1. Said transmission power amplifying means amplifying degree is formed by the variable power amplifier is controlled, the output level of the variable power amplifier is capable of transmitting and receiving of the first and status transmission and reception that may due to the frequency a second frequency The simplex radio according to claim 2, which is different from a state.

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