JP2021150773A - Radio loud speaker system and loud speaking slave station - Google Patents

Abstract

To implement a radio loud speaker system using a 260 MHz band without generating the deterioration of a voice signal.SOLUTION: A loud speaking slave station 40 includes: a base station communication unit 42 which receives from a base station 30 a base station communication signal in which a voice signal is distributed into three slots; and three inter-slave station communication units which are a first inter-slave station communication unit 44A, a second inter-slave station communication unit 44B and a third inter-slave station communication unit 44C, as communication units to communicate with other loud speaking slave stations 40. When the base station communication unit 42 receives a base station communication signal, an adjustment unit 41, based on the above signal, causes an inter-slave station communication signal generator unit 45 to generate first, second and third signals, which are signals (inter-slave station communication signals) to be transmitted respectively from the first, second and third inter-slave station communication units 44A, 44B, 44C to the other loud speaking slave stations 40 (40B).SELECTED DRAWING: Figure 2

Description

The present invention relates to a wireless loudspeaker system that performs wireless communication in order to perform disaster prevention broadcasting and the like at a plurality of locations, and a loudspeaker station used therefor.

A disaster prevention broadcast that is broadcast simultaneously by a plurality of loudspeakers installed separately on the ground is particularly effective in an emergency such as a tsunami. In this case, a plurality of loudspeaker stations are provided corresponding to each loudspeaker, and the loudspeaker station receives a broadcast signal (audio signal) emitted from the base station by wireless communication to perform broadcasting.

At this time, the range in which wireless communication with the base station is possible (base area) is determined according to the base station, and wireless communication becomes difficult outside the base area. In this case, a relay station that relays wireless communication is installed between the base station and the loudspeaker station, whereby the base area can be substantially widened. Such a wireless loudspeaker system for disaster prevention has been established using a frequency in the 60 MHz band in the wireless communication standard of ARIB (Association of Radio Industries and Businesses) STD-T86.

On the other hand, although it is not used as a loudspeaker system as described above, various public wireless communication systems such as those in the 260 MHz band are also used. The wireless communication standard in the 260 MHz band is described in ARIB STD-T79 and is different from that in the 60 MHz band described above. Such 260 MHz band communication is used for other public purposes other than the loudspeaker system described above, and is used as wireless communication for transmitting and receiving various data between a base station and a mobile station and between mobile stations. There is.

Since the applicable wireless communication standards are different, it is not possible to construct a wireless loudspeaker system in the 260 MHz band by changing only the carrier frequency in, for example, a wireless loudspeaker system using the 60 MHz band. For example, in the technique described in Patent Document 1, it is an issue that the audio codec implemented in the mobile communication system is not suitable for loudspeaker broadcasting, and in the case of loudspeaker broadcasting, it is higher than the audio codec used in non-loud broadcasting. It is encoded by a bit rate audio codec. As a result, the loudspeaker station can perform loudspeaker broadcasting on the mobile wireless communication system as in the case of using the 60 MHz band.

Further, in the technique described in Patent Document 2, a loudspeaker audio signal is encoded by an audio codec having a bit rate higher than that of a non-loud audio codec, and a larger number of slots are allocated than the non-loud audio signal. By transmitting the audio codec, it is possible to perform high-quality loudspeaker broadcasting even in a mobile wireless communication system.

Japanese Unexamined Patent Publication No. 2012-175256 Japanese Patent No. 5723162

In the 260 MHz band wireless system defined by ARIB STD-T79, the communication area is expanded by relaying the signal to the terminal station in the area where the base station communication signal does not reach by using the direct communication signal. There is a function. However, the direct communication signal can transmit only one slot of data in one frame. Therefore, when transmitting a loudspeaker broadcast signal having a large data size as in the techniques described in Patent Documents 1 and 2, it cannot be relayed because it does not fit in the direct communication signal.

The present invention has been made in view of such a situation, and an object of the present invention is to solve the above problems.

The wireless loudspeaker system of the present invention includes a base station that transmits a base station communication signal in which voice signals are distributed to a plurality of slots in one frame of the TDMA system to a first loudspeaker station, and the base station to the base station. A first loudspeaker station that receives a station communication signal and transmits a plurality of slave station communication signals, which are distributed to a plurality of slots and the voice signals are distributed to slots of different carriers, to a second loudspeaker station. A second loudspeaker station that receives a plurality of inter-substation communication signals from the first loudspeaker station and acquires the voice signal from the plurality of inter-substation communication signals.
The loudspeaker station of the present invention receives a base station communication signal from a base station in which audio signals are distributed to a plurality of slots in one frame of the TDMA system, and the audio signals distributed to the plurality of slots are different from each other. The communication signals between a plurality of slave stations distributed in the slots of the carrier wave are transmitted to another loudspeaker slave station.

According to the present invention, it is possible to construct a wireless loudspeaker system using the 260 MHz band without causing deterioration of the voice signal.

It is a figure which shows the structure of the wireless loudspeaker system which concerns on embodiment. It is a figure which shows the structure of the loudspeaker station used in the wireless loudspeaker system which concerns on embodiment. It is a format of a base station communication signal in the wireless loudspeaker system according to the embodiment. This is a format of communication signals (first signal, second signal, third signal) between slave stations in the wireless loudspeaker system according to the embodiment.

Next, a mode for carrying out the present invention will be specifically described. FIG. 1 shows the configuration of the wireless loudspeaker system 1 according to the embodiment of the present invention. In the wireless loudspeaker system 1, the loudspeaker control stand 10 digitally converts (encodes) the loudspeaker broadcast voice (various alarms, etc.) input by the user's operation and transmits it to the control station control device 20. The control station control device 20 manages the entire wireless loudspeaker system 1 and transmits the encoded voice signal to the base station 30 in a predetermined communication format. The loudspeaker control stand 10 and the control station control device 20 are both composed of computers, and signals are exchanged between the loudspeaker control stand 10, the control station control device 20, and the base station 30 by wired communication, short-range wireless communication, or the like. .. The base station 30 emits a signal received from the control station control device 20 as a base station communication signal.

In this wireless loudspeaker system 1, a plurality of loudspeaker stations 40 are used. The loudspeaker stations 40 are arranged at remote locations on the ground, and loudspeakers 50 are provided corresponding to each. Therefore, when the loudspeaker station 40 obtains the audio signal, the audio signal can be output from the loudspeaker 50 to perform disaster prevention broadcasting or the like. However, the loudspeaker station 40 and the corresponding loudspeaker 50 do not have to be close to each other. For example, the loudspeaker 50 may be fixed on the ground and the loudspeaker station 40 may be portable. In FIG. 1, two typical sets of the loudspeaker station 40 and the loudspeaker 50 are shown, but in reality, a larger number of sets are provided.

The base station 30 and the loudspeaker station 40 are connected by long-distance wireless communication. Therefore, the loudspeaker station 40 capable of communicating with the base station 30 is limited to those in the communicable area A (loudspeaker station 40A in FIG. 1). However, the loudspeaker station 40 not only receives a signal (base station communication signal) from the base station 30, but also has a function (relay function) of relaying this signal and transmitting it to another loudspeaker station 40. .. Therefore, the above-mentioned voice signal can be transmitted to the loudspeaker station 40 (loudspeaker station 40B) outside the communicable area A, whereby the substantially communicable area can be expanded. Further, since the loudspeaker station 40B can also transmit this audio signal to another loudspeaker station 40, many loudspeakers 50 other than those shown in FIG. 1 can also broadcast by this audio signal. can do.

Here, the communication between the base station 30 and the loudspeaker station 40 and between the loudspeaker stations 40 is performed in accordance with the 260 MHz band wireless communication standard described in ARIB STD-T79. That is, the communication between the base station 30 and the loudspeaker station 40 (base station communication) is performed in the communication format of the base station communication in ARIB STD-T79. On the other hand, communication between loudspeaker stations 40 (communication between slave stations) is performed in the communication format of direct communication between mobile stations in ARIB STD-T79.

Here, in the communication between the base station and the slave station of the present invention (base station communication), carriers having different frequencies are used for uplink and downlink, and they are connected in multiple access by the TDMA method. In the transmission of the signal from the base station 30 side to the loudspeaker station 40 (40A), one frame is time-divisioned into four slots. In this embodiment, the encoded data is transmitted simultaneously in three slots. On the other hand, in the communication between slave stations (communication between slave stations), the format is different from that of base station communication, and communication of only one slot in one frame is possible. Therefore, the loudspeaker station 40A cannot relay the signal received from the base station 30 side as it is and transmit it to the loudspeaker station 40B.

Therefore, the loudspeaker station 40 (40A) has a function of converting a signal received from the base station 30 and transmitting it to another loudspeaker station 40 (40B).

FIG. 2 is a block diagram showing the configuration of the loudspeaker station 40, which is a common configuration of the loudspeaker stations 40A and 40B in FIG. The loudspeaker station 40 is provided with an adjusting unit 41 that adjusts signals and controls each component as described below. Further, a base station communication unit 42 for communicating with the base station 30 (base station communication) and receiving the base station communication signal is provided. As described above, the base station communication is performed in the communication format between the control station and the mobile station in ARIB STD-79, and the physical channel for communication is for downlink communication described in ARIB STD-79, and This communication takes place in 3 slots. Therefore, the signal format of the signal (base station communication signal) transmitted from the base station 30 is as shown in FIG. Here, 320 bits are used in each slot, and in FIG. 3, each item name and the distribution of the number of bits are shown. Definitions of R, P, TCH, etc. in the item are those described in ARIB STD-79.

Here, the encoded audio signal (audio file) to be transmitted as described above is sorted into the TCH items (A to F) in FIG. Actually, the signals in each of these slots are simultaneously transmitted from the base station 30 to the loudspeaker station 40, and the base station communication unit 42 of the loudspeaker station 40 (40A) receives and adjusts the base station communication signals in the three slots. The unit 41 acquires the audio files A to F from this signal and transmits them to the decoding unit 43, and the decoding unit 43 decodes the audio signal from this and outputs it. The loudspeaker 50 connected to the loudspeaker station 40A in FIG. 1 can obtain and output this audio signal.

Further, the loudspeaker station 40 (40A) is a communication unit for communicating with another loudspeaker station 40 (40B), the first slave station communication unit 44A and the second slave station communication unit 44B. , The third slave station communication unit 44C is provided. The first slave station communication unit 44A, the second slave station communication unit 44B, and the third slave station communication unit 44C each independently communicate in the communication format between slave stations in ARIB STD-79 ( Transmission and reception), and carrier waves with different frequencies are used.

When the base station communication unit 42 receives the above base station communication signal, the coordinating unit 41 uses the signal as a basis for the first slave station communication unit 44A, the second slave station communication unit 44B, and the third child. The first signal, the second signal, and the third signal, which are signals (inter-substation communication signals) transmitted from each of the inter-station communication units 44C to the other loudspeaker stations 40 (40B), are transmitted to the inter-station communication signal creation unit 45. To create. These signals are different from the base station communication signals (FIG. 3) obtained by the base station communication unit 42.

FIG. 4 shows an inter-slave communication signal (first signal, second signal, third signal) created by the inter-slave communication signal creation unit 45 when the base station communication unit 42 obtains the signal shown in FIG. The format of the signal) is shown. This format is the same as the physical channel for direct communication in the communication between slave stations in ARIB STD-79. Here, in each communication unit, only one slot out of one frame is used. Here, the contents of the above A to F are divided into TCH items in each signal for each signal and divided into two.

In each of these signals, 320 bits are used as in the above-mentioned base station communication signal, but the item and the number of bits assigned to the item are different. However, the content of A and the content of B in FIG. 3 are the first signal in FIG. 4, the content of C and the content of D are the second signal in FIG. 4, and the content of E and the content of F are the third signal in FIG. It can be incorporated into the signal. At this time, for example, the TCH in FIG. 4 is further divided and some bits are used as a header, and it is possible to specify in this header that this signal is a voice signal divided in this way. Although the number of TCH bits in FIG. 3 and the number of TCH bits in FIG. 4 do not match, by setting the header in this way, the first signal or the like is created or the audio signal is reliably decoded using the header. be able to.

In FIG. 1, the first inter-substation communication unit 44A, the second inter-substation communication unit 44B, and the third inter-substation communication unit 44C in the loudspeaker station 40A are individually described as the first signal and the second signal, respectively. , The third signal is transmitted respectively. Since these are signals transmitted at different frequencies, they can be transmitted at the same time.

On the other hand, the loudspeaker station 40B in FIG. 1 has the same configuration as the loudspeaker station 40A (FIG. 2). At this time, the first slave station communication unit 44A, the second slave station communication unit 44B, and the third slave station communication unit 44C in the loudspeaker station 40B and the loudspeaker station 40A are in the 260 MHz band as described above. Communication can be done individually. That is, for example, the first inter-substation communication unit 44A on the loudspeaker station 40A side calls the first inter-substation communication unit 44A on the loudspeaker station 40B side, and then the first inter-substation communication unit on the loudspeaker station 40A side. The first signal is emitted from 44A toward the first inter-substation communication unit 44A on the loudspeaker station 40B side. The same applies to the second slave station communication unit 44B and the second slave station communication unit 44C, and similarly, the second signal and the third signal are emitted.

When the first signal, the second signal, and the third signal are available on the loudspeaker station 40B side, the adjusting unit 41 on the loudspeaker station 40B side recognizes A'to F'in FIG. 4 from these. be able to. As a result, the decoding unit 43 of the loudspeaker station 40B on the loudspeaker station 40B side can decode and output the audio signal as in the case of receiving the base station communication signal.

Further, since the loudspeaker station 40B has the same configuration as the loudspeaker station 40A, the first slave station communication unit 44A, the second slave station communication unit 44B, and the third slave station communication in the loudspeaker station 40B. The unit 44C can transmit the received first signal, second signal, and third signal to the other loudspeaker stations 40 as they are. As a result, the voice signal is transmitted to many loudspeaker stations 40. In this case, the loudspeaker station 40B has a function as a relay device.

In the above operation, A to F transmitted by the base station communication signal are also transmitted as they are in the communication between the loudspeaker stations 40 by the first signal, the second signal, and the third signal. Therefore, unlike the technique described in Patent Document 1, for example, deterioration of the voice signal does not occur.

Further, as described above, the 260 MHz band wireless communication is used for transmitting and receiving various data for public use other than as a loudspeaker system. On the other hand, in the above-mentioned wireless loudspeaker system 1, the base station in the system normally used in this way is made to transmit the base station communication signal for transmitting the above-mentioned audio signal, and FIG. This can be easily achieved by connecting to the loudspeaker 50 using the loudspeaker station 40 shown. As a result, disaster prevention broadcasting, etc., which was conventionally performed using the 60 MHz band, can be realized even in the 260 MHz band, which enhances the convenience of disaster prevention broadcasting, or even if a failure occurs in the wireless loudspeaker system in the 60 MHz band. , Disaster prevention broadcasting can be performed reliably.

The present invention has been described above based on the embodiments. This embodiment is an example, and it will be understood by those skilled in the art that various modifications are possible for the combination of each of these components, and that such modifications are also within the scope of the present invention.

1 Wireless loudspeaker system 10 Loudspeaker control stand 20 Control station control device 30 Base stations 40, 40A, 40B Loudspeaker station 41 Coordinating unit 42 Base station communication unit 43 Decoding unit 44A First slave station communication unit (inter-substation communication unit)
44B Second slave station communication unit (slave station communication unit)
44C Third slave station communication unit (slave station communication unit)
45 Inter-substation communication signal creation unit 50 Loudspeaker

Claims (4)

A base station that transmits a base station communication signal in which audio signals are distributed to a plurality of slots in one frame of the TDMA system to a first loudspeaker station, and a base station.
The base station communication signal is received from the base station, and the communication signal between the plurality of slave stations, which is the voice signal distributed to the plurality of slots and distributed to the slots of different carrier waves, is transmitted to the second loudspeaker station. The first loudspeaker station and
A second loudspeaker station that receives a plurality of inter-slave communication signals from the first loudspeaker and acquires the voice signal from the plurality of inter-slave communication signals.
Wireless loudspeaker system with. The first loudspeaker station is characterized in that the voice signal distributed to a plurality of slots of the base station communication signal is decoded into one voice signal and the decoded voice signal is loudened. Wireless loudspeaker system. A base station communication signal in which audio signals are distributed to a plurality of slots within one frame of the TDMA system is received from the base station.
A loudspeaker station characterized by transmitting a communication signal between a plurality of slave stations in which the voice signals distributed in a plurality of slots are distributed to slots of different carrier waves to another loudspeaker station. The loudspeaker station according to claim 3, wherein the voice signal distributed to a plurality of slots of the base station communication signal is decoded into one voice signal, and the decoded voice signal is loudened.

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