CN113519128B

CN113519128B - FM communication device, radio communication device, TDMA communication device, and FM communication method

Info

Publication number: CN113519128B
Application number: CN202080018347.2A
Authority: CN
Inventors: 八本大希
Original assignee: Furuno Electric Co Ltd
Current assignee: Furuno Electric Co Ltd
Priority date: 2019-03-13
Filing date: 2020-02-13
Publication date: 2023-05-30
Anticipated expiration: 2040-02-13
Also published as: JPWO2020184041A1; WO2020184041A1; CN113519128A; JP7265615B2

Abstract

Noise generated in FM demodulation is suppressed when transmitted in TDMA fashion. The FM communication device comprises an FM demodulation unit (32), a TDMA transmission detection unit (34F), and an output sound control unit (35). An FM demodulation unit (32) demodulates an FM communication signal received by an antenna capable of receiving a TDMA signal and an FM communication signal with overlapping frequency bands. A TDMA transmission detection unit (34F) detects that a TDMA signal is being transmitted. An output sound control unit (35) uses the detection result of the TDMA transmission detection unit (34F) to control the output sound from the FM demodulation unit (32) when the TDMA signal is being transmitted.

Description

FM communication device, radio communication device, TDMA communication device, and FM communication method

Technical Field

The present invention relates to a radio communication device which is realized by using an antenna common to TDMA (Time division multiple access: time division multiple access) communication such as AIS (Automatic Identification System: automatic identification system) and FM (Frequency Modulation: frequency modulation) communication such as VHF (Very High Frequency: very high frequency) communication, and an FM communication device which constitutes the radio communication device and performs FM communication.

Background

Patent document 1 describes a wireless communication device. The wireless communication device described in patent document 1 performs VHF communication and AIS communication. The frequency band of VHF communication overlaps with the frequency band of AIS communication. Thus, VHF communication and AIS communication are performed through one antenna.

The VHF receiving unit and the AIS communication unit are connected to the antenna via a splitter. When receiving the VHF radio signal, the splitter connects the VHF receiving portion to the antenna. When AIS communication is performed, the splitter connects the AIS communication unit to the antenna.

Prior art literature

Patent literature

Patent document 1: united kingdom patent application publication No. 2460012.

Disclosure of Invention

Problems to be solved by the invention

The AIS communication adopts TDMA (Time division multiple access) mode. Therefore, the AIS communication unit transmits the AIS signal when the transmission time arrives. When the AIS signal is being transmitted, the connection between the VHF receiving unit and the antenna is cut off. That is, the conventional wireless communication device described in patent document 1 does not output a wireless signal to the VHF reception unit when performing AIS communication.

However, since the VHF reception unit uses the FM demodulation method, if no radio signal is input, the level of the input signal drops sharply, and noise is generated.

Accordingly, an object of the present invention is to provide a technique for suppressing noise generated in FM demodulation when transmitting in a TDMA system.

Means for solving the problems

An FM communication device according to the present invention comprises: an FM demodulation unit, a TDMA transmission detection unit, and an output sound control unit. The FM demodulation unit demodulates an FM communication signal received by an antenna capable of receiving a TDMA signal and an FM communication signal with overlapping frequency bands. A TDMA transmission detecting section detects that a TDMA signal is being transmitted. The output sound control unit uses the detection result of the TDMA transmission detection unit to control the output sound from the FM demodulation unit when the TDMA signal is being transmitted.

In this configuration, when the TDMA signal is being transmitted, the output of noise generated in FM demodulation is controlled.

Effects of the invention

According to the present invention, noise generated in FM demodulation when transmitting in TDMA can be suppressed. In particular, it is possible to suppress noise at the time of insertion of the AIS communication in a very short time at the time of VHF radio reception.

Drawings

Fig. 1 is a functional block diagram showing the structure of a wireless communication device according to a first embodiment.

Fig. 2 (a) and (B) are diagrams showing a first embodiment of a change in output sound.

Fig. 3 is a flowchart showing an embodiment of a communication method of VHF radio signals.

Fig. 4 is a functional block diagram showing the structure of a wireless communication device according to a second embodiment.

Fig. 5 is a functional block diagram showing the structure of a wireless communication device according to a third embodiment.

Fig. 6 is a diagram showing a second embodiment of the change in output sound.

Fig. 7 is a flowchart showing an embodiment of a communication method of VHF radio signals.

Fig. 8 is a functional block diagram showing the structure of a wireless communication device according to the fourth embodiment.

Fig. 9 is a functional block diagram showing the structure of a wireless communication device according to the fifth embodiment.

Fig. 10 is a functional block diagram showing the structure of a wireless communication device according to the sixth embodiment.

Fig. 11 is a functional block diagram showing the structure of a wireless communication device according to the seventh embodiment.

Fig. 12 is a functional block diagram showing the structure of a wireless communication device according to an eighth embodiment.

Detailed Description

(first embodiment)

A radio communication device according to a first embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a functional block diagram showing the structure of a wireless communication device according to a first embodiment.

As shown in fig. 1, the wireless communication apparatus 10 includes: an antenna 100, a VHF splitter 20, a VHF wireless device 30, and an AIS transceiver 40. The VHF splitter 20 corresponds to the "splitter" of the present invention. The VHF radio 30 corresponds to "FM communication device" or "FM communication unit" of the present invention. The AIS transceiver 40 corresponds to the "TDMA communication section" of the present invention.

The antenna 100 is connected to the VHF splitter 20. The VHF splitter 20 is connected to the VHF wireless device 30 and the AIS transceiver 40.

The antenna 100 transmits and receives VHF radio signals and AIS signals. The frequency band of the VHF wireless signal overlaps with the frequency band of the AIS signal.

The AIS transceiver 40 transmits and receives AIS signals in a TDMA fashion.

(construction of VHF splitter 20 and Signal processing)

The VHF splitter 20 has: a distributor 21, a switching circuit 22, a demultiplexer 23, and a switching state detecting unit 24. The distributor 21 is connected to the antenna 100 and the switching circuit 22. The switching circuit 22 is connected to the demultiplexer 23 and the AIS transceiver 40. The demultiplexer 23 is connected to the VHF wireless device 30. The switching state detecting unit 24 is connected to the switching circuit 22 and the demultiplexer 23.

The distributor 21 outputs the wireless signal from the antenna 100 to two terminals in the switch circuit 22. The two terminals are terminals connected to the dispenser 21. The distributor 21 outputs a wireless signal output from one of the two terminals to the antenna 100. In addition, the distributor 21 outputs a wireless signal output from the other of the two terminals to the antenna 100.

When transmitting the AIS signal, the switching circuit 22 disconnects the splitter 21 from the demultiplexer 23.

The switch circuit 22 connects the distributor 21 to the demultiplexer 23 at a time other than when the AIS signal is transmitted.

The switching circuit 22 disconnects the splitter 21 from the AIS transceiver 40 when the VHF signal is transmitted.

The switch circuit 22 connects the distributor 21 to the AIS transceiver 40 at a time other than when the VHF signal is transmitted.

With this configuration, the VHF splitter 20 connects the AIS transceiver 40 to the antenna 100 when transmitting the AIS signal. In addition, the VHF splitter 20 disconnects the VHF wireless device 30 from the antenna 100 when transmitting the AIS signal.

On the other hand, when transmitting VHF signals, VHF splitter 20 disconnects AIS transceiver 40 from antenna 100. In addition, the VHF splitter 20 connects the VHF wireless device 30 with the antenna 100 when transmitting the VHF signal. Furthermore, when neither the AIS signal nor the VHF signal is transmitted, the VHF splitter 20 connects both the VHF wireless device 30 and the AIS transceiver 40 with the antenna 100.

The switching state detecting section 24 detects the switching state of the switching circuit 22, and outputs a switching state detection signal to the demultiplexer 23. If the demultiplexer 23 (VHF wireless device 30) is not connected to the distributor 21 (antenna 100), the switching state detecting section 24 outputs a switching state detection signal. If the demultiplexer 23 (VHF wireless device 30) is connected to the distributor 21 (antenna 100), the switching state detecting section 24 stops outputting the switching state detection signal. The switching state detection signal is, for example, a dc voltage signal having a predetermined level (not 0). The switching state detection signal is a voltage signal of a different frequency from the VHF radio signal, and is not limited to a dc voltage signal if the VHF radio signal can be demultiplexed.

The demultiplexer 23 combines the signal from the switching circuit 22 side and the signal from the switching state detecting unit 24, and outputs the resultant signal to the VHF wireless device 30. Thus, the demultiplexer 23 outputs the VHF wireless signal to the VHF wireless device 30 at a time other than when the AIS signal is transmitted. When transmitting the AIS signal, the demultiplexer 23 outputs a switching state detection signal to the VHF wireless device 30.

(Structure of VHF Wireless device 30 and Signal processing)

The VHF wireless device 30 has: a demultiplexer 31, an FM demodulation unit 32, an amplifier 33, an AIS transmission detection unit 34, an output sound control unit 35, a variable amplifier 36, and a speaker 37. The AIS transmission detection unit 34 corresponds to a "TDMA transmission detection unit" of the present invention. Although fig. 1 only shows the VHF wireless signal receiving function in the VHF wireless device 30, the VHF wireless device 30 may have a VHF wireless signal transmitting function unit.

The demultiplexer 31 is connected to the demultiplexer 23 of the VHF splitter 20. The demultiplexer 31 is connected to an FM demodulation unit 32 and an AIS transmission detection unit 34. The FM demodulation unit 32 is connected to an input terminal of the amplifier 33. The output terminal of the amplifier 33 is connected to an output sound control unit 35. The AIS transmission detection unit 34 is connected to an output sound control unit 35. The output sound control unit 35 is connected to an input terminal of the variable amplifier 36. The output of the variable amplifier 36 is connected to a speaker 37.

The demultiplexer 31 has a filter function. The demultiplexer 31 outputs the VHF radio signal to the FM demodulation unit 32, but not to the AIS transmission detection unit 34. The demultiplexer 31 outputs the switching state detection signal to the AIS transmission detection section 34, but not to the FM demodulation section 32.

The FM demodulation unit 32 demodulates the VHF radio signal and outputs the demodulated VHF radio signal to the amplifier 33. The amplifier 33 amplifies the demodulated signal and outputs the amplified signal to the output sound control unit 35.

When the AIS transmission detection unit 34 detects the switching state detection signal, it generates an on signal and outputs the on signal to the output sound control unit 35. If the AIS transmission detection unit 34 does not detect the switching state detection signal, it does not output an on signal. The on signal is, for example, a dc voltage signal of a predetermined level, and is a signal exceeding the on level of the and gate 351 described later.

The output sound control unit 35 includes: and gate 351, switching element 352, switching element 353, and attenuator 354. The ENABLE signal is input into a first input terminal of the and gate 351. A second input terminal of the and gate 351 is connected to the AIS transmission detecting unit 34. The output terminal of the and gate 351 is connected to the switching element 352 and the switching element 353.

The switching element 352 has: a common terminal, a first selection terminal, and a second selection terminal. The switching element 352 selects either one of the first selection terminal and the second selection terminal to be connected to the common terminal.

The switching element 353 has: a common terminal, a third selection terminal, and a fourth selection terminal. The switching element 353 selects any one of the third selection terminal and the fourth selection terminal to be connected to the common terminal.

The common terminal of the switching element 352 is connected to the output terminal of the amplifier 33. The first selection terminal of the switching element 352 is connected to the third selection terminal of the switching element 353. The second selection terminal of the switching element 352 is connected to the fourth selection terminal of the switching element 353 via an attenuator 354. The common terminal of the switching element 353 is connected to the input terminal of the variable amplifier 36.

The attenuator 354 is a resistor or the like, and suppresses the level of an input signal.

When the on signal from the AIS transmission detector 34 is input, the and gate 351 outputs a switch changeover signal.

If the switch changeover signal is not input, the switching element 352 connects the common terminal with the first selection terminal. If the switch changeover signal is input, the switching element 352 connects the common terminal with the second selection terminal.

If the switch changeover signal is not input, the switching element 353 connects the common terminal with the third selection terminal. If the switch changeover signal is input, the switching element 353 connects the common terminal with the fourth selection terminal.

Thus, switching element 352 and switching element 353 are directly connected if not while the AIS signal is being transmitted. That is, if not while the AIS signal is being transmitted, the output of amplifier 33 is connected to the input of variable amplifier 36, not via attenuator 354.

On the other hand, if the switching element 352 and the switching element 353 are connected via the attenuator 354 while the AIS signal is being transmitted. That is, if the output of amplifier 33 is connected to the input of variable amplifier 36 via attenuator 354 while the AIS signal is being transmitted.

The variable amplifier 36 amplifies the input signal according to the set gain and outputs the amplified signal to the speaker 37. The speaker 37 converts the output signal of the variable amplifier 36 into sound and sounds.

With such a configuration and control, the VHF wireless device 30 can achieve the following operational effects.

Specifically, with the above configuration and control, if the AIS signal is not being transmitted, the output sound control unit 35 outputs the VHF radio signal without being suppressed by the attenuator 354. On the other hand, if the AIS signal is being transmitted, the output sound control unit 35 suppresses noise generated by the FM demodulation unit 32 by the attenuator 354 and outputs the suppressed noise.

Thus, the output sound changes as shown in fig. 2 (a) and 2 (B). Fig. 2 (a) and 2 (B) are diagrams showing a first embodiment of a change in output sound.

As shown in fig. 2 a and 2B, during the time when the AIS signal is not being transmitted (the AIS transmission period in fig. 2B), the VHF wireless device 30 outputs the VHF sound after FM demodulation from the VHF wireless signal at a predetermined level (amplitude). When the AIS signal is being transmitted, the VHF wireless device 30 suppresses noise generated by the FM demodulation unit 32 and outputs the suppressed noise. As shown in fig. 2 (a) and 2 (B), the level (amplitude) of noise is lower than the level of VHF sound. On the other hand, in the conventional configuration in which this control is not performed, the level of noise is much greater than the level of VHF sound.

In this way, the VHF wireless device 30 can suppress noise generated when VHF wireless communication is interrupted due to transmission of the AIS signal. In particular, the AIS signal is inserted in a very short time compared to the time when the VHF sound is emitted. Specifically, the transmission period of the AIS signal is 80msec at the maximum. The noise inserted in VHF sound is harsh. However, with this configuration, the VHF wireless device 30 can suppress the offensive noise, and can make a call or the like by VHF sound comfortable.

(first mode of communication method of VHF Wireless signals)

In the above description, each process performed by the VHF wireless device 30 is performed by a separate functional unit. However, the above-described processes may be programmed and stored, and the arithmetic processing device may execute the program. In this case, for example, the arithmetic processing device may execute the flowchart shown in fig. 3. Fig. 3 is a flowchart showing an embodiment of a communication method of VHF radio signals. In fig. 3, the state of receiving the VHF radio signal is set to the start state.

The arithmetic processing device receives the VHF radio signal (S11). When the arithmetic processing device detects the start of transmission of the AIS signal (S12: YES), the arithmetic processing device suppresses the level of the output sound (S13). When the start of transmission of the AIS signal is not detected (NO in S12), the arithmetic processing device does not suppress the level of the output sound.

In the suppression of the level, the arithmetic processing device resumes the level of the output sound (S15) when detecting the end of the transmission of the AIS signal (S14: yes). The restoration of the level of the output sound is suppression of the level of the stop output sound. When the transmission end of the AIS signal is not detected (S14: NO), the arithmetic processing device continues the suppression of the level of the output sound.

(second embodiment)

A wireless communication device according to a second embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 4 is a functional block diagram showing the structure of a wireless communication device according to a second embodiment.

As shown in fig. 4, the radio communication apparatus 10A of the second embodiment is different from the radio communication apparatus 10 of the first embodiment in the configuration of the VHF radio device 30A. The basic structure of the wireless communication apparatus 10A is the same as that of the wireless communication apparatus 10, and the description of the same parts is omitted.

The VHF wireless device 30A has: the VHF splitter 20A, FM includes a demodulation unit 32, an amplifier 33, an AIS transmission detection unit 34A, an output sound control unit 35, a variable amplifier 36, and a speaker 37. That is, the VHF wireless device 30A has the structure of the VHF wireless device 30 and the structure of the VHF splitter 20 shown in the first embodiment in one housing.

The AIS transmission detecting section 34A is connected to the switching circuit 22. The AIS transmission detection unit 34A realizes the functions of the switching state detection unit 24 and the AIS transmission detection unit 34 shown in the first embodiment. More specifically, for example, if the FM demodulation unit 32 is not connected to the distributor 21 (antenna 100), the AIS transmission detection unit 34A generates an on signal and outputs the on signal to the output sound control unit 35. If the FM demodulation unit 32 is connected to the distributor 21 (antenna 100), the AIS transmission detection unit 34A does not output an on signal.

Even with such a configuration, the VHF wireless device 30A can function and effect similar to those of the VHF wireless device 30 shown in the first embodiment. Further, the radio communication apparatus 10A can reduce the number of components compared with the radio communication apparatus 10 of the first embodiment.

(third embodiment)

A wireless communication device according to a third embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 5 is a functional block diagram showing the structure of a wireless communication device according to a third embodiment.

As shown in fig. 5, the radio communication apparatus 10B of the third embodiment is different from the radio communication apparatus 10 of the first embodiment in the configuration of the VHF radio device 30B. Other structures of the wireless communication apparatus 10B are the same as those of the wireless communication apparatus 10, and the description of the same parts is omitted.

The VHF wireless device 30B has: the demultiplexer 31, AIS transmission detecting unit 34, variable amplifier 36, speaker 37, DSP325, AD converting unit 381, and DA converting unit 382. The demultiplexer 31 is connected to the demultiplexer 23 of the VHF splitter 20. The demultiplexer 31 is connected to the AIS transmission detector 34 and the AD converter 381. The AD converter 381 and the AIS transmission detector 34 are connected to the DSP 325.

DSP325 is a programmable signal processing circuit. The DSP325 has: FM demodulation unit 32B, and output sound control unit 35B. The FM demodulation unit 32B is connected to the AD conversion unit 381. The FM demodulation unit 32B is connected to the output sound control unit 35B. The output sound control unit 35B is connected to the DA conversion unit 382. The DA converter 382 is connected to the input terminal of the variable amplifier 36. The output of the variable amplifier 36 is output to a speaker 37.

The AD converter 381 converts the VHF radio signal composed of an analog signal into a digital signal, and outputs the digital signal to the FM demodulator 32B. The FM demodulation unit 32B demodulates the VHF radio signal and outputs the demodulated VHF radio signal to the output sound control unit 35B.

If the on signal is not received from the AIS transmission detection unit 34, the output sound control unit 35B amplifies the VHF radio signal and outputs it. That is, the output sound control unit 35B amplifies the VHF radio signal and outputs the amplified VHF radio signal during a period other than the transmission period of the AIS signal.

When the on signal is received from the AIS transmission detection unit 34, the output sound control unit 35B suppresses the level of noise output from the FM demodulation unit 32B and outputs the suppressed noise.

Further, if the on signal is received from the AIS transmission detection unit 34, the output sound control unit 35B may replace the noise output from the FM demodulation unit 32B with white noise and output the same. In this case, the level (amplitude) of the white noise is preferably the same as the amplitude of the VHF radio signal. In addition, the present invention is not limited to white noise, and other audio signals may be used. As the other audio signal, for example, an analog audio signal obtained by filtering white noise, a replica signal of an audio signal before switching, or the like can be used.

That is, when the AIS signal is being transmitted, the output sound control unit 35B suppresses the FM demodulated noise and outputs the suppressed FM demodulated noise, or outputs white noise.

The DA converter 382 converts an output signal of the output sound control unit 35B, which is composed of a digital signal, into an analog signal, and outputs the analog signal to the variable amplifier 36.

Thus, even if the output sound control section 35B is realized by a programmable signal processing circuit, the VHF wireless device 30B functions and effects similar to those of the VHF wireless device 30.

In addition, the VHF wireless device 30B replaces the FM demodulated noise by outputting white noise that does not easily become harsh, thereby playing the same role and effect as the VHF wireless device 30.

Fig. 6 is a diagram showing a second embodiment of the change in output sound. As shown in fig. 6, during a period when the AIS signal is not being transmitted (AIS transmission period in fig. 6), the VHF wireless device 30B outputs VHF sound after FM demodulation from the VHF wireless signal at a predetermined level (amplitude). In addition, while the AIS signal is being transmitted, the VHF wireless device 30B outputs white noise instead of the noise generated by the FM demodulation section 32. As shown in fig. 6, the level (amplitude) of the white noise is substantially the same as the level of the VHF sound.

Further, the output sound control section 35B can execute delay processing. By this delay processing, the output sound control unit 35B can ensure a delay in the start timing of suppression of the FM demodulation noise. Therefore, the output sound control unit 35B can more reliably output noise with suppressed level. Alternatively, by this delay processing, the output sound control unit 35B can ensure a delay in the start timing of white noise switching with respect to the FM-demodulated noise. Therefore, the output sound control unit 35B can more reliably output white noise instead of FM-demodulated noise.

(second mode of communication method of VHF Wireless signals)

In the above description, each process performed by the VHF wireless device 30B is performed by a separate functional unit. However, the above-described processes may be programmed and stored, and the arithmetic processing device may execute the program. In this case, for example, the arithmetic processing device may execute the flowchart shown in fig. 7. Fig. 7 is a flowchart showing an embodiment of a communication method of VHF radio signals. In fig. 7, the state of receiving the VHF radio signal is set to the start state. Fig. 7 shows a scheme in which FM-demodulated noise is replaced with white noise.

The arithmetic processing device receives the VHF radio signal (S11). When the arithmetic processing device detects the start of transmission of the AIS signal (S12: yes), the arithmetic processing device is replaced with white noise (S21). When the start of transmission of the AIS signal is not detected (NO in S12), the arithmetic processing device does not perform replacement with white noise.

When the arithmetic processing device detects that the transmission of the AIS signal is completed during the replacement to the white noise (S14: yes), the arithmetic processing device completes the replacement to the white noise (S22). When the transmission end of the AIS signal is not detected (S14: NO), the arithmetic processing device continues the replacement with white noise.

(fourth embodiment)

A radio communication device according to a fourth embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 8 is a functional block diagram showing the structure of a wireless communication device according to the fourth embodiment.

As shown in fig. 8, a wireless communication apparatus 10C according to the fourth embodiment differs from the wireless communication apparatus 10 according to the first embodiment in that it has an AIS communication apparatus 400. The basic configuration of the wireless communication apparatus 10C is the same as that of the wireless communication apparatus 10, and the description of the same parts is omitted.

The AIS communication apparatus 400 has an AIS transceiver 40 and a VHF splitter 20. That is, the AIS communication device 400 has the structure of the AIS transceiver 40 and the VHF splitter 20 shown in the first embodiment in one housing.

Even with such a configuration, the wireless communication apparatus 10C can provide the same operational effects as those of the wireless communication apparatus 10 according to the first embodiment. Further, the radio communication apparatus 10C can reduce the number of components compared with the radio communication apparatus 10 of the first embodiment.

(fifth embodiment)

A wireless communication device according to a fifth embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 9 is a functional block diagram showing the structure of a wireless communication device according to the fifth embodiment.

As shown in fig. 9, the wireless communication device 10D according to the fifth embodiment differs from the wireless communication device 10C according to the fourth embodiment in the connection method of the switching state detecting unit 24. Other configurations of the wireless communication apparatus 10D are the same as those of the wireless communication apparatus 10, and the description of the same parts is omitted.

When the AIS transmission signal is detected from the AIS transceiver 40, the switching state detection unit 24 outputs a switching state detection signal to the demultiplexer 23. For example, when detecting that the signal level output from the AIS transceiver 40 is equal to or higher than a predetermined level, the switching state detecting unit 24 detects that the AIS transmission signal is being transmitted. When the AIS transmission signal is not detected from the AIS transceiver 40, the switching state detecting section 24 does not output the switching state detection signal to the demultiplexer 23.

Even with such a configuration, the wireless communication apparatus 10D can provide the same operational effects as the wireless communication apparatus 10C.

(sixth embodiment)

A radio communication device according to a sixth embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 10 is a functional block diagram showing the structure of a wireless communication device according to the sixth embodiment.

As shown in fig. 10, the wireless communication device 10E according to the sixth embodiment differs from the wireless communication device 10 according to the first embodiment in the method of generating the on signal in the VHF splitter 20E and the AIS transmission detecting unit 34E. Other structures of the wireless communication apparatus 10E are the same as those of the wireless communication apparatus 10, and the description of the same parts is omitted.

The VHF splitter 20E has a distributor 21 and a switching circuit 22. The switch circuit 22 is connected to the distributor 21, the AIS transceiver 40, and the FM demodulation unit 32 of the VHF wireless device 30C. That is, the VHF splitter 20E has a structure in which the demultiplexer 23 and the switching state detector 24 are omitted from the VHF splitter 20 of the first embodiment.

The VHF wireless device 30E has a structure in which the demultiplexer 31 is omitted from the VHF wireless device 30 of the first embodiment. The AIS transmission detection unit 34E is connected to the AIS transceiver 40.

The AIS transmission detection unit 34E generates an on signal when the AIS transmission signal is input from the AIS transceiver 40, and outputs the on signal to the output sound control unit 35. For example, the AIS transmission detection unit 34E determines that the AIS transmission signal is inputted when detecting that the level of the input signal is equal to or higher than a predetermined level. The AIS transmission detection unit 34E does not generate an on signal unless an AIS communication signal (transmission signal) is input from the AIS transceiver 40.

Even with such a configuration, the wireless communication apparatus 10E can provide the same operational effects as the wireless communication apparatus 10.

(seventh embodiment)

A radio communication device according to a seventh embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 11 is a functional block diagram showing the structure of a wireless communication device according to the seventh embodiment.

As shown in fig. 11, the radio communication apparatus 10F of the seventh embodiment is different from the radio communication apparatus 10 of the first embodiment in that it has a VHF radio device 30F. Other structures of the wireless communication apparatus 10F are the same as those of the wireless communication apparatus 10, and description of the same parts is omitted

The VHF wireless device 30F has: a demultiplexer 31, an FM demodulation unit 32, an AIS transmission detection unit 34F, a variable amplifier 36, and a speaker 37. The FM demodulation unit 32 is connected to an input terminal of the variable amplifier 36.

If the AIS transmission detection unit 34F detects the switching state detection signal, it generates an on signal and outputs the on signal to the variable amplifier 36. The on signal is a signal that decreases the gain of the variable amplifier 36. The AIS transmission detection unit 34F does not generate the on signal if the switching state detection signal is not detected.

Thereby, the gain of the variable amplifier 36 is not reduced.

With this configuration, the VHF wireless device 30F suppresses FM-demodulated noise during AIS transmission and outputs VHF sounds at a predetermined level during a period other than AIS transmission. That is, the VHF wireless device 30F functions and effects similar to those of the VHF wireless device 30 shown in the first embodiment.

(eighth embodiment)

A radio communication device according to an eighth embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 12 is a functional block diagram showing the structure of a wireless communication device according to an eighth embodiment.

The above embodiments illustrate a wireless communication device that will communicate an AIS signal and a VHF wireless signal. However, the AIS signal may be other TDMA signals, and the VHF wireless signal may be FM communication signals of other frequency bands. At this time, the band of the TDMA signal overlaps with the band of the VHF wireless signal.

The basic structure and processing of the radio communication apparatus 10G according to the eighth embodiment are the same as those of the radio communication apparatus 10 according to the first embodiment, and the description of the same parts is omitted.

As shown in fig. 12, the wireless communication apparatus 10G includes: antenna 100, splitter 20G, FM wireless device 30G, and TDMA communication device 40G.

The splitter 20G has: a distributor 21, a switching circuit 22, a demultiplexer 23, and a switching state detecting unit 24. The FM radio device 30G has: a demultiplexer 31, an FM demodulation unit 32, an amplifier 33, a TDMA communication detection unit 34G, an output sound control unit 35, a variable amplifier 36, and a speaker 37.

The TDMA communication device 40G performs the same processing of the TDMA communication signal as the AIS transceiver 40 of the first embodiment. The TDMA communication detection section 34G performs the same processing as the AIS transmission detection section 34 of the first embodiment.

In this way, even when the TDMA signal and the FM communication signal are communicated by 1 antenna 100, noise at the time of FM demodulation can be suppressed by the configuration of the wireless communication apparatus 10G.

The structures of the above embodiments can be appropriately combined, and the operational effects corresponding to the combination can be obtained.

Description of the reference numerals

10. 10A, 10B, 10C, 10D, 10E, 10F, 10G wireless communication device

20. 20E VHF splitter

20G branching unit

21. Dispenser

22. Switching circuit

23. Wave separator

24. Switching state detecting unit

30. 30A, 30B, 30C, 30E, 30F VHF wireless device

30G FM radio device

31. Wave separator

32. 32B FM demodulation unit

33. Amplifier

34. 34C, 34E, 34F AIS transmission detecting section

34G TDMA communication detection part

35. 35B output Sound control section

36. Variable amplifier

37. Loudspeaker

40 AIS transceiver

40G TDMA communication equipment

100. Antenna

325 DSP

351. AND gate

352. 353 switch element

354. Attenuator

381 AD conversion unit

382 DA conversion unit

400 AIS communication device

Terminology

Not all objects or effects/advantages may be achieved in accordance with any particular embodiment described in this specification. Thus, for example, those skilled in the art will recognize that a particular embodiment may be configured to operate in a manner that achieves or optimizes one advantage or group of effects or advantages as taught or suggested herein without necessarily achieving other objects or effects or advantages as may be taught or suggested herein.

All of the processes described in this specification are implemented in software code modules that are executed by a computing system comprising one or more computers or processors, thereby achieving complete automation. The code modules can be stored in any type of non-transitory computer readable medium or other computer storage device. Some or all of the methods can be implemented by dedicated computer hardware.

As is clear from the present disclosure, there are many other modifications other than those described in the present specification. For example, according to the embodiments, any one specific action, event or function of the algorithms described in the present specification may be executed at different timings, and may be added, combined or completely excluded (for example, not all the described actions or events need to be executed). Additionally, in particular embodiments, actions or events can be performed in parallel, rather than serially, for example, via multiple processors or processor cores, or on other parallel architectures, as well as multithreaded processing, interrupt processing, or the like. In addition, different tasks or processes can be performed by different machines and/or computing systems that can function together.

The various illustrative logical blocks and modules described in connection with the embodiments disclosed herein may be implemented or performed by a machine, such as a processor. A processor may also be a microprocessor, but in the alternative, the processor may be a controller, a microcontroller, or a state machine, or a combination of the same. The processor can include circuitry configured to process the computer-executable commands. In another embodiment, the processor comprises an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or other programmable device that performs logic operations without processing computer-executable instructions. A processor can also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor (digital signal processing apparatus) and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In this specification, the digital technology is mainly described, but the processor can also mainly include analog elements. For example, part or all of the signal processing algorithms described in this specification can be implemented by analog circuits, or a hybrid of analog and digital circuits. The computing environment includes a microprocessor, mainframe computer, digital signal processor, portable computing device, device controller, or computing engine-based computer system within the appliance, but can include any type of computer system not limited to these.

Unless otherwise indicated, references to conditional language such as "capable of", "completing", "about" or "having the potential to" are to be construed as in the general context of usage to convey that a particular embodiment includes a particular feature, element, and/or step, but does not include the meaning of other embodiments. Thus, in general, such conditional language does not imply that features, elements and/or steps are any method for more than one embodiment nor that more than one embodiment necessarily contains logic for determining whether such features, elements and/or steps are contained in or are performed by any particular embodiment.

The optional language of the word "at least one of X, Y, Z," unless specified otherwise, is to be understood in the context of the term "optionally" as used herein to mean an item, the term, etc., may be any one of X, Y, Z or any combination thereof (e.g., X, Y, Z). Thus, such selective language does not generally imply that each particular embodiment requires the presence of at least one of X, at least one of Y, or at least one of Z.

Any process descriptions, elements, or functional blocks in the flow charts described in this specification and/or shown in the figures are understood to include any portions of the underlying modules, segments, or code that are used to implement the particular logic function or element in the process. Alternative embodiments are included within the scope of the embodiments described in this specification, where elements or functions may be deleted from the illustrated or described flow in substantially the same or opposite order, or performed in a different order, depending on the functionality associated, as will be understood by those skilled in the art.

The words "a" and "an" should generally be interpreted to include more than one of the described items, unless specifically stated otherwise. Accordingly, the phrase "a device as set forth above" and the like is intended to encompass more than one of the devices listed. Such one or more enumerated devices may also be collectively configured to execute the recited references. For example, the "processor configured to execute A, B and C below" may include a first processor configured to execute a and a second processor configured to execute B and C. Furthermore, even if a specific number of an introduced embodiment is explicitly recited, those skilled in the art should interpret such recitation as typically implying at least the recited number (e.g., a mere recitation of "two recitations," without the use of other modifiers, typically refers to at least two recitations or more than two recitations).

In general, the terms used in this specification are generally intended to be "non-limiting" terms (e.g., the term "comprising" should be interpreted as "not only, but also as" having at least, "the term" having "should be interpreted as" including, but not limited to, "although including the following), as will be appreciated by those skilled in the art.

For the purposes of this specification, the term "horizontal" is defined as a plane parallel to the plane or surface of the floor of the area in which the illustrated system is used, or a plane in which the illustrated method is implemented, regardless of its orientation. The term "floor" can be replaced with the term "ground" or "water surface". The term "vertical" refers to a direction perpendicular to a defined horizontal line. Terms such as "upper", "lower", "upper", "side", "higher", "lower", "above", "beyond", "lower" and the like are defined with respect to a horizontal plane.

The terms "attached," "connected," "paired," and other related terms used in this specification should be construed to include detachably, movably, fixedly, adjustably, and/or detachably connected or linked as long as there is no additional comment. The connection/tie includes a connection having a direct connection and/or an intermediate configuration between the two structural members described.

The terms "substantially," "about," and "substantially" as used herein include the recited amounts unless otherwise specified, and also refer to amounts of material approaching those recited for performing the desired function or achieving the desired result. For example, "substantially", "about" and "substantially" refer to values less than 10% of the recited values unless otherwise specifically indicated. As used in this specification, the terms "substantially", "about" and "substantially" and the like are intended to refer also to the features of the disclosed embodiments as performing the desired function or as having variability in achieving the desired result for its features.

Many variations and modifications can be added to the above-described embodiments, and it should be understood that these elements are in other permissible examples. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.

Claims

1. An FM communication device, comprising:

an FM demodulation unit for demodulating an FM communication signal received by an antenna capable of receiving a TDMA signal and an FM communication signal having overlapping frequency bands;

a TDMA transmission detection unit configured to detect that the TDMA signal transmitted in a state where the antenna is disconnected from the FM demodulation unit is being transmitted; and

and an output sound control unit that controls the output sound from the FM demodulation unit when the TDMA signal is being transmitted, using the detection result of the TDMA transmission detection unit.

2. The FM communications apparatus of claim 1, wherein,

the output sound control unit decreases a gain for the output sound when the TDMA signal is being transmitted.

3. The FM communications apparatus of claim 1, wherein,

the output sound control unit replaces the output sound with white noise when the TDMA signal is being transmitted.

4. The FM communications apparatus of claim 1, wherein,

the output sound control unit delays the output sound from the FM demodulation unit.

5. The FM communication device according to any one of claims 1 to 4, further comprising:

and a switching circuit connected between the antenna and the FM demodulation unit, for switching between communication based on the TDMA signal and communication based on the FM communication signal.

6. The FM communications apparatus of claim 5, wherein,

the TDMA transmission detecting section detects that the TDMA signal is being transmitted, based on a switching state of the switching circuit.

7. The FM communication device according to any one of claims 1-4, wherein,

the TDMA transmission detection section detects that the TDMA signal is being transmitted, using the level of the TDMA signal.

8. The FM communication device according to any one of claims 1-4, wherein,

the TDMA signal is an AIS signal,

the FM communication signal is a VHF radio signal.

9. A wireless communication apparatus, comprising:

an antenna for transmitting and receiving a TDMA signal and an FM communication signal with overlapping frequency bands;

a TDMA communication unit for communicating the TDMA signal;

an FM radio unit comprising: an FM demodulation unit for demodulating the FM communication signal; a TDMA transmission detection unit configured to detect that the TDMA signal transmitted in a state where the antenna is disconnected from the FM demodulation unit is being transmitted; and an output sound control unit that controls an output sound when the TDMA signal is being transmitted, using a detection result of the TDMA transmission detection unit; and

and a splitter for switching the TDMA communication unit and the FM radio unit to connect to the antenna.

10. The wireless communications apparatus of claim 9, wherein,

the splitter and the FM radio are housed in the same housing.

11. The wireless communications apparatus of claim 9, wherein,

the splitter and the TDMA communication section are housed in the same housing.

12. The wireless communication device according to any one of claims 9 to 11, wherein,

the splitter has a switching circuit that switches the TDMA communication section and the FM radio section so as to be connected to the antenna,

13. The wireless communications apparatus of claim 12, wherein,

the splitter further has a switching state detection section that detects the switching state, generates a switching state detection signal,

the TDMA transmission detection unit detects that the TDMA signal is being transmitted, using the switching state detection signal.

14. The wireless communication device according to any one of claims 9 to 11, wherein,

15. The wireless communication device according to any one of claims 9 to 11, wherein,

the TDMA signal is an AIS signal,

the FM communication signal is a VHF radio signal.

16. A TDMA communication apparatus, comprising:

a TDMA communication unit for communicating with the TDMA signal;

a branching unit for switching transmission paths of the TDMA communication unit and the FM communication signal overlapping the TDMA signal band so as to be connected to an antenna; and

and a switching state detecting unit configured to detect that the TDMA signal based on the TDMA communication unit transmitted in a state where the antenna is disconnected from the demodulation unit of the FM communication signal is being transmitted, and to output TDMA transmission information indicating that the TDMA signal is being transmitted.

17. A TDMA communication apparatus according to claim 16 wherein,

the switching state detecting section outputs the TDMA transmission information to a transmission path of the FM communication signal.

18. An FM communication method, wherein,

demodulating the FM communication signal received by an antenna capable of receiving the TDMA signal and the FM communication signal with overlapping frequency bands,

detecting that the TDMA signal transmitted in a state where the antenna is disconnected from the demodulation section of the FM communication signal is being transmitted,

using a detection result based on the transmission of the TDMA signal, the output sound demodulated from the FM communication signal is controlled while the TDMA signal is being transmitted.